refactor(snix): address upcoming clippy lints

This uses variables inside `format!()` strings directly,
and switches to using `std::io::Error::other(e.to_string())`
instead of std::io::Error::new(io::ErrorKind::Other, e.to_string()).

It also found an unnecessary `mut` in the test harness.

Change-Id: I406c709091e87ec64bfbdbcdc7f460af9b83d3bc
Reviewed-on: https://cl.snix.dev/c/snix/+/30630
Autosubmit: Florian Klink <flokli@flokli.de>
Tested-by: besadii
Reviewed-by: Ryan Lahfa <ryan@lahfa.xyz>

snix/build/src/buildservice/dummy.rs

@@ -11,8 +11,7 @@ pub struct DummyBuildService {}
 impl BuildService for DummyBuildService {
     #[instrument(skip(self), ret, err)]
     async fn do_build(&self, _request: BuildRequest) -> std::io::Result<BuildResult> {
-        Err(std::io::Error::new(
+        Err(std::io::Error::other(
-            std::io::ErrorKind::Other,
             "builds are not supported with DummyBuildService",
         ))
     }

snix/build/src/buildservice/from_addr.rs

@@ -24,8 +24,8 @@ where
     BS: BlobService + Send + Sync + Clone + 'static,
     DS: DirectoryService + Send + Sync + Clone + 'static,
 {
-    let url = Url::parse(uri)
+    let url =
-        .map_err(|e| std::io::Error::other(format!("unable to parse url: {}", e)))?;
+        Url::parse(uri).map_err(|e| std::io::Error::other(format!("unable to parse url: {e}")))?;
 
     Ok(match url.scheme() {
         // dummy doesn't care about parameters.

snix/build/src/buildservice/oci.rs

@@ -132,10 +132,7 @@ where
 
             warn!(stdout=%stdout, stderr=%stderr, exit_code=%child_output.status, "build failed");
 
-            return Err(std::io::Error::new(
+            return Err(std::io::Error::other("nonzero exit code".to_string()));
-                std::io::ErrorKind::Other,
-                "nonzero exit code".to_string(),
-            ));
         }
 
         // Ingest build outputs into the castore.
@@ -161,7 +158,7 @@ where
                         .map_err(|e| {
                             std::io::Error::new(
                                 std::io::ErrorKind::InvalidData,
-                                format!("Unable to ingest output: {}", e),
+                                format!("Unable to ingest output: {e}"),
                             )
                         })?,
 

snix/build/src/oci/spec.rs

@@ -125,7 +125,7 @@ fn configure_process<'a>(
         .args(command_args)
         .env(
             env.into_iter()
-                .map(|(k, v)| format!("{}={}", k, v))
+                .map(|(k, v)| format!("{k}={v}"))
                 .collect::<Vec<_>>(),
         )
         .terminal(true)

snix/build/src/oci/subuid.rs

@@ -115,7 +115,7 @@ mod tests {
         use std::io::Write;
         let mut file = tempfile::NamedTempFile::new().expect("Could not create tempfile");
         for line in content.into_iter() {
-            writeln!(file, "{}", line).expect("");
+            writeln!(file, "{line}").expect("");
         }
         file
     }

snix/castore/src/blobservice/from_addr.rs

@@ -20,7 +20,7 @@ pub async fn from_addr(
     uri: &str,
 ) -> Result<Arc<dyn BlobService>, Box<dyn std::error::Error + Send + Sync>> {
     let url = Url::parse(uri)
-        .map_err(|e| crate::Error::StorageError(format!("unable to parse url: {}", e)))?;
+        .map_err(|e| crate::Error::StorageError(format!("unable to parse url: {e}")))?;
 
     let blob_service_config = with_registry(&REG, || {
         <DeserializeWithRegistry<Box<dyn ServiceBuilder<Output = dyn BlobService>>>>::try_from(url)

snix/castore/src/blobservice/grpc.rs

@@ -64,7 +64,7 @@ where
         {
             Ok(_blob_meta) => Ok(true),
             Err(e) if e.code() == Code::NotFound => Ok(false),
-            Err(e) => Err(io::Error::new(io::ErrorKind::Other, e)),
+            Err(e) => Err(io::Error::other(e)),
         }
     }
 
@@ -106,7 +106,7 @@ where
                             Ok(Some(Box::new(Cursor::new(buf))))
                         }
                         Err(e) if e.code() == Code::NotFound => Ok(None),
-                        Err(e) => Err(io::Error::new(io::ErrorKind::Other, e)),
+                        Err(e) => Err(io::Error::other(e)),
                     };
                 }
 
@@ -175,7 +175,7 @@ where
 
         match resp {
             Err(e) if e.code() == Code::NotFound => Ok(None),
-            Err(e) => Err(io::Error::new(io::ErrorKind::Other, e)),
+            Err(e) => Err(io::Error::other(e)),
             Ok(resp) => {
                 let resp = resp.into_inner();
 
@@ -259,15 +259,14 @@ impl<W: tokio::io::AsyncWrite + Send + Sync + Unpin + 'static> BlobWriter for GR
                     // return the digest from the response, and store it in self.digest for subsequent closes.
                     let digest_len = resp.digest.len();
                     let digest: B3Digest = resp.digest.try_into().map_err(|_| {
-                        io::Error::new(
+                        io::Error::other(format!(
-                            io::ErrorKind::Other,
+                            "invalid root digest length {digest_len} in response"
-                            format!("invalid root digest length {} in response", digest_len),
+                        ))
-                        )
                     })?;
                     self.digest = Some(digest.clone());
                     Ok(digest)
                 }
-                Err(e) => Err(io::Error::new(io::ErrorKind::Other, e.to_string())),
+                Err(e) => Err(io::Error::other(e.to_string())),
             }
         }
     }

snix/castore/src/blobservice/tests/mod.rs

@@ -98,7 +98,7 @@ async fn put_has_get(blob_service: impl BlobService) {
             "blob service should now have the blob"
         );
 
-        let mut r = blob_service
+        let r = blob_service
             .open_read(blob_digest)
             .await
             .expect("open_read must succeed")

snix/castore/src/composition.rs

@@ -155,7 +155,7 @@ impl<'r, 'de: 'r, T: 'static> SeedFactory<'de, TagString<'de>> for RegistryWithF
             .0
             .iter()
             .find(|(k, _)| *k == &(TypeId::of::<T>(), tag.as_ref()))
-            .ok_or_else(|| serde::de::Error::custom(format!("Unknown type: {}", tag)))?
+            .ok_or_else(|| serde::de::Error::custom(format!("Unknown type: {tag}")))?
             .1;
 
         let entry: &RegistryEntry<T> = <dyn Any>::downcast_ref(&**seed).unwrap();

snix/castore/src/directoryservice/bigtable.rs

@@ -202,7 +202,7 @@ impl DirectoryService for BigtableDirectoryService {
         let mut response = client
             .read_rows(request)
             .await
-            .map_err(|e| Error::StorageError(format!("unable to read rows: {}", e)))?;
+            .map_err(|e| Error::StorageError(format!("unable to read rows: {e}")))?;
 
         if response.len() != 1 {
             if response.len() > 1 {
@@ -244,17 +244,14 @@ impl DirectoryService for BigtableDirectoryService {
         // For the data in that cell, ensure the digest matches what's requested, before parsing.
         let got_digest = B3Digest::from(blake3::hash(&row_cell.value).as_bytes());
         if got_digest != *digest {
-            return Err(Error::StorageError(format!(
+            return Err(Error::StorageError(format!("invalid digest: {got_digest}")));
-                "invalid digest: {}",
-                got_digest
-            )));
         }
 
         // Try to parse the value into a Directory message.
         let directory = proto::Directory::decode(Bytes::from(row_cell.value))
-            .map_err(|e| Error::StorageError(format!("unable to decode directory proto: {}", e)))?
+            .map_err(|e| Error::StorageError(format!("unable to decode directory proto: {e}")))?
             .try_into()
-            .map_err(|e| Error::StorageError(format!("invalid Directory message: {}", e)))?;
+            .map_err(|e| Error::StorageError(format!("invalid Directory message: {e}")))?;
 
         Ok(Some(directory))
     }
@@ -301,7 +298,7 @@ impl DirectoryService for BigtableDirectoryService {
                 ],
             })
             .await
-            .map_err(|e| Error::StorageError(format!("unable to mutate rows: {}", e)))?;
+            .map_err(|e| Error::StorageError(format!("unable to mutate rows: {e}")))?;
 
         if resp.predicate_matched {
             trace!("already existed")
@@ -376,7 +373,7 @@ impl TryFrom<url::Url> for BigtableParameters {
             .append_pair("instance_name", &instance_name);
 
         let params: BigtableParameters = serde_qs::from_str(url.query().unwrap_or_default())
-            .map_err(|e| Error::InvalidRequest(format!("failed to parse parameters: {}", e)))?;
+            .map_err(|e| Error::InvalidRequest(format!("failed to parse parameters: {e}")))?;
 
         Ok(params)
     }

snix/castore/src/directoryservice/from_addr.rs

@@ -28,7 +28,7 @@ pub async fn from_addr(
 ) -> Result<Arc<dyn DirectoryService>, Box<dyn std::error::Error + Send + Sync>> {
     #[allow(unused_mut)]
     let mut url = Url::parse(uri)
-        .map_err(|e| crate::Error::StorageError(format!("unable to parse url: {}", e)))?;
+        .map_err(|e| crate::Error::StorageError(format!("unable to parse url: {e}")))?;
 
     let directory_service_config = with_registry(&REG, || {
         <DeserializeWithRegistry<Box<dyn ServiceBuilder<Output = dyn DirectoryService>>>>::try_from(

snix/castore/src/directoryservice/grpc.rs

@@ -71,8 +71,7 @@ where
                 let actual_digest = directory.digest();
                 if actual_digest != digest {
                     Err(crate::Error::StorageError(format!(
-                        "requested directory with digest {}, but got {}",
+                        "requested directory with digest {digest}, but got {actual_digest}"
-                        digest, actual_digest
                     )))
                 } else {
                     Ok(Some(directory.try_into().map_err(|_| {
@@ -141,8 +140,7 @@ where
                             // it if it's in received_directory_digests (as that
                             // means it once was in expected_directory_digests)
                             Err(crate::Error::StorageError(format!(
-                                "received unexpected directory {}",
+                                "received unexpected directory {directory_digest}"
-                                directory_digest
                             )))?;
                         }
                         received_directory_digests.insert(directory_digest);
@@ -177,8 +175,7 @@ where
                         // If this is not empty, then the closure is incomplete
                         if diff_len != 0 {
                             Err(crate::Error::StorageError(format!(
-                                "still expected {} directories, but got premature end of stream",
+                                "still expected {diff_len} directories, but got premature end of stream"
-                                diff_len
                             )))?
                         } else {
                             return

snix/castore/src/directoryservice/memory.rs

@@ -34,13 +34,12 @@ impl DirectoryService for MemoryDirectoryService {
                 let actual_digest = directory.digest();
                 if actual_digest != *digest {
                     return Err(Error::StorageError(format!(
-                        "requested directory with digest {}, but got {}",
+                        "requested directory with digest {digest}, but got {actual_digest}"
-                        digest, actual_digest
                     )));
                 }
 
                 Ok(Some(directory.clone().try_into().map_err(|e| {
-                    crate::Error::StorageError(format!("corrupted directory: {}", e))
+                    crate::Error::StorageError(format!("corrupted directory: {e}"))
                 })?))
             }
         }

snix/castore/src/directoryservice/object_store.rs

@@ -152,8 +152,7 @@ impl DirectoryService for ObjectStoreDirectoryService {
                         // Ensure to only decode the directory objects whose digests we trust
                         if !order_validator.digest_allowed(&digest) {
                             return Err(crate::Error::StorageError(format!(
-                                "received unexpected directory {}",
+                                "received unexpected directory {digest}"
-                                digest
                             )));
                         }
 

snix/castore/src/directoryservice/tests/mod.rs

@@ -167,7 +167,7 @@ async fn put_get_foo(directory_service: impl DirectoryService) {
         ],
     ];
     if !valid_closures.contains(&retrieved_closure) {
-        panic!("invalid closure returned: {:?}", retrieved_closure);
+        panic!("invalid closure returned: {retrieved_closure:?}");
     }
 }
 

snix/castore/src/directoryservice/traverse.rs

@@ -26,7 +26,7 @@ where
                     // If we didn't get the directory node that's linked, that's a store inconsistency, bail out!
                     warn!(directory.digest = %digest, "directory does not exist");
 
-                    Error::StorageError(format!("directory {} does not exist", digest))
+                    Error::StorageError(format!("directory {digest} does not exist"))
                 })?;
 
                 // look for the component in the [Directory].

snix/castore/src/directoryservice/utils.rs

@@ -33,8 +33,7 @@ pub fn traverse_directory<'a, DS: DirectoryService + 'static>(
             let current_directory = match directory_service.get(&current_directory_digest).await.map_err(|e| {
                 warn!("failed to look up directory");
                 Error::StorageError(format!(
-                    "unable to look up directory {}: {}",
+                    "unable to look up directory {current_directory_digest}: {e}"
-                    current_directory_digest, e
                 ))
             })? {
                 // the root node of the requested closure was not found, return an empty list
@@ -43,8 +42,7 @@ pub fn traverse_directory<'a, DS: DirectoryService + 'static>(
                 None => {
                     warn!("directory {} does not exist", current_directory_digest);
                     Err(Error::StorageError(format!(
-                        "directory {} does not exist",
+                        "directory {current_directory_digest} does not exist"
-                        current_directory_digest
                     )))?;
                     break;
                 }

snix/castore/src/errors.rs

@@ -78,7 +78,7 @@ impl From<Error> for Status {
     fn from(value: Error) -> Self {
         match value {
             Error::InvalidRequest(msg) => Status::invalid_argument(msg),
-            Error::StorageError(msg) => Status::data_loss(format!("storage error: {}", msg)),
+            Error::StorageError(msg) => Status::data_loss(format!("storage error: {msg}")),
         }
     }
 }
@@ -140,7 +140,7 @@ impl From<Error> for std::io::Error {
     fn from(value: Error) -> Self {
         match value {
             Error::InvalidRequest(msg) => Self::new(std::io::ErrorKind::InvalidInput, msg),
-            Error::StorageError(msg) => Self::new(std::io::ErrorKind::Other, msg),
+            Error::StorageError(msg) => Self::other(msg),
         }
     }
 }

snix/castore/src/fs/fuse/mod.rs

@@ -76,13 +76,13 @@ impl FuseDaemon {
         let server = Arc::new(fuse_backend_rs::api::server::Server::new(Arc::new(fs)));
 
         let mut session = FuseSession::new(mountpoint.as_ref(), "snix-castore", "", true)
-            .map_err(|e| io::Error::new(io::ErrorKind::Other, e.to_string()))?;
+            .map_err(|e| io::Error::other(e.to_string()))?;
 
         #[cfg(target_os = "linux")]
         session.set_allow_other(allow_other);
         session
             .mount()
-            .map_err(|e| io::Error::new(io::ErrorKind::Other, e.to_string()))?;
+            .map_err(|e| io::Error::other(e.to_string()))?;
 
         // construct a thread pool
         let threads = threadpool::Builder::new()
@@ -99,7 +99,7 @@ impl FuseDaemon {
                 server: server.clone(),
                 channel: session
                     .new_channel()
-                    .map_err(|e| io::Error::new(io::ErrorKind::Other, e.to_string()))?,
+                    .map_err(|e| io::Error::other(e.to_string()))?,
             };
 
             // Start the FuseServer in each thread, and enter the tokio runtime context,
@@ -131,7 +131,7 @@ impl FuseDaemon {
         self.session
             .lock()
             .umount()
-            .map_err(|e| io::Error::new(io::ErrorKind::Other, e.to_string()))?;
+            .map_err(|e| io::Error::other(e.to_string()))?;
 
         self.wait();
         Ok(())

snix/castore/src/fs/virtiofs.rs

@@ -54,7 +54,7 @@ impl error::Error for Error {}
 
 impl convert::From<Error> for io::Error {
     fn from(e: Error) -> Self {
-        io::Error::new(io::ErrorKind::Other, e)
+        io::Error::other(e)
     }
 }
 
@@ -195,7 +195,7 @@ where
                 queue
                     .get_queue_mut()
                     .enable_notification(self.guest_mem.memory().deref())
-                    .map_err(|e| io::Error::new(io::ErrorKind::Other, e.to_string()))?;
+                    .map_err(|e| io::Error::other(e.to_string()))?;
                 if !self.process_queue(&mut queue)? {
                     break;
                 }

snix/castore/src/import/fs.rs

@@ -143,7 +143,7 @@ where
 
     // convert to castore PathBuf
     let path = crate::path::PathBuf::from_host_path(fs_path, false)
-        .unwrap_or_else(|e| panic!("Snix bug: walkdir direntry cannot be parsed: {}", e));
+        .unwrap_or_else(|e| panic!("Snix bug: walkdir direntry cannot be parsed: {e}"));
 
     if file_type.is_dir() {
         Ok(IngestionEntry::Dir { path })
@@ -166,7 +166,7 @@ where
         let digest = upload_blob(blob_service, entry.path().to_path_buf(), reference_scanner)
             .instrument({
                 let span = info_span!("upload_blob", "indicatif.pb_show" = tracing::field::Empty);
-                span.pb_set_message(&format!("Uploading blob for {:?}", fs_path));
+                span.pb_set_message(&format!("Uploading blob for {fs_path:?}"));
                 span.pb_set_style(&snix_tracing::PB_TRANSFER_STYLE);
 
                 span

snix/castore/src/import/mod.rs

@@ -98,7 +98,7 @@ where
                     Err(e) => {
                         return Err(IngestionError::UploadDirectoryError(
                             path,
-                            crate::Error::StorageError(format!("invalid symlink target: {}", e)),
+                            crate::Error::StorageError(format!("invalid symlink target: {e}")),
                         ));
                     }
                 }

snix/castore/src/proto/grpc_directoryservice_wrapper.rs

@@ -53,7 +53,7 @@ where
                                 tonic::Status::new(tonic::Code::Internal, e.to_string())
                             })?
                             .ok_or_else(|| {
-                                Status::not_found(format!("directory {} not found", digest))
+                                Status::not_found(format!("directory {digest} not found"))
                             })?;
 
                         Box::pin(once(Ok(directory.into())))

snix/cli/src/repl.rs

@@ -155,7 +155,7 @@ impl<'a> Repl<'a> {
                 Err(ReadlineError::Interrupted) | Err(ReadlineError::Eof) => break,
 
                 Err(err) => {
-                    writeln!(stderr, "error: {}", err).unwrap();
+                    writeln!(stderr, "error: {err}").unwrap();
                     break;
                 }
             }

snix/eval/src/builtins/mod.rs

@@ -542,7 +542,7 @@ mod pure_builtins {
         let len = length.as_int()?;
         let mut out = Vec::with_capacity(
             len.try_into()
-                .map_err(|_| ErrorKind::Abort(format!("can not create list of size {}", len)))?,
+                .map_err(|_| ErrorKind::Abort(format!("can not create list of size {len}")))?,
         );
 
         // the best span we can get…
@@ -655,17 +655,17 @@ mod pure_builtins {
                 for ctx_element in group {
                     match ctx_element {
                         NixContextElement::Plain(spath) => {
-                            debug_assert!(spath == key, "Unexpected group containing mixed keys, expected: {:?}, encountered {:?}", key, spath);
+                            debug_assert!(spath == key, "Unexpected group containing mixed keys, expected: {key:?}, encountered {spath:?}");
                             is_path = true;
                         }
 
                         NixContextElement::Single { name, derivation } => {
-                            debug_assert!(derivation == key, "Unexpected group containing mixed keys, expected: {:?}, encountered {:?}", key, derivation);
+                            debug_assert!(derivation == key, "Unexpected group containing mixed keys, expected: {key:?}, encountered {derivation:?}");
                             outputs.push(name.clone().into());
                         }
 
                         NixContextElement::Derivation(drv_path) => {
-                            debug_assert!(drv_path == key, "Unexpected group containing mixed keys, expected: {:?}, encountered {:?}", key, drv_path);
+                            debug_assert!(drv_path == key, "Unexpected group containing mixed keys, expected: {key:?}, encountered {drv_path:?}");
                             all_outputs = true;
                         }
                     }
@@ -992,7 +992,7 @@ mod pure_builtins {
         }
         let re = re.to_str()?;
         let re = re.to_str()?;
-        let re: Regex = cached_regex(&format!("^{}$", re))
+        let re: Regex = cached_regex(&format!("^{re}$"))
             .map_err(|_| ErrorKind::InvalidRegex(re.to_string()))?;
 
         match re.captures(s.to_str()?) {

snix/eval/src/builtins/to_xml.rs

@@ -298,15 +298,15 @@ mod tests {
     fn xml_escape() {
         match XmlEmitter::<Writer<Vec<u8>>>::escape_attr_value("ab<>c&de") {
             Cow::Owned(s) => assert_eq!(s, "ab&lt;&gt;c&amp;de".to_string(), "escape stuff"),
-            Cow::Borrowed(s) => panic!("s should be owned {}", s),
+            Cow::Borrowed(s) => panic!("s should be owned {s}"),
         }
         match XmlEmitter::<Writer<Vec<u8>>>::escape_attr_value("") {
             Cow::Borrowed(s) => assert_eq!(s, "", "empty escape is borrowed"),
-            Cow::Owned(s) => panic!("s should be borrowed {}", s),
+            Cow::Owned(s) => panic!("s should be borrowed {s}"),
         }
         match XmlEmitter::<Writer<Vec<u8>>>::escape_attr_value("hi!ŷbla") {
             Cow::Borrowed(s) => assert_eq!(s, "hi!ŷbla", "no escape is borrowed"),
-            Cow::Owned(s) => panic!("s should be borrowed {}", s),
+            Cow::Owned(s) => panic!("s should be borrowed {s}"),
         }
         match XmlEmitter::<Writer<Vec<u8>>>::escape_attr_value("hi!<ŷ>bla") {
             Cow::Owned(s) => assert_eq!(
@@ -314,7 +314,7 @@ mod tests {
                 "hi!&lt;ŷ&gt;bla".to_string(),
                 "multi-byte chars are correctly used"
             ),
-            Cow::Borrowed(s) => panic!("s should be owned {}", s),
+            Cow::Borrowed(s) => panic!("s should be owned {s}"),
         }
     }
 }

snix/eval/src/chunk.rs

@@ -172,40 +172,40 @@ impl Chunk {
         if idx.0 > 0 && source.get_line(self.get_span(idx - 1)) == line {
             write!(writer, "   |\t")?;
         } else {
-            write!(writer, "{:4}\t", line)?;
+            write!(writer, "{line:4}\t")?;
         }
 
         let _fmt_constant = |idx: ConstantIdx| match &self.constants[idx.0] {
             Value::Thunk(t) => t.debug_repr(),
             Value::Closure(c) => format!("closure({:p})", c.lambda),
-            Value::Blueprint(b) => format!("blueprint({:p})", b),
+            Value::Blueprint(b) => format!("blueprint({b:p})"),
-            val => format!("{}", val),
+            val => format!("{val}"),
         };
 
         let op: Op = self.code[idx.0].into();
 
         match op.arg_type() {
             OpArg::None => {
-                writeln!(writer, "Op{:?}", op)?;
+                writeln!(writer, "Op{op:?}")?;
                 Ok(1)
             }
 
             OpArg::Fixed => {
                 let arg = self.read_u16(idx.0 + 1);
-                writeln!(writer, "Op{:?}({})", op, arg)?;
+                writeln!(writer, "Op{op:?}({arg})")?;
                 Ok(3)
             }
 
             OpArg::Uvarint => {
                 let (arg, size) = self.read_uvarint(idx.0 + 1);
-                writeln!(writer, "Op{:?}({})", op, arg)?;
+                writeln!(writer, "Op{op:?}({arg})")?;
                 Ok(1 + size)
             }
 
             _ => match op {
                 Op::CoerceToString => {
                     let kind: CoercionKind = self.code[idx.0 + 1].into();
-                    writeln!(writer, "Op{:?}({:?})", op, kind)?;
+                    writeln!(writer, "Op{op:?}({kind:?})")?;
                     Ok(2)
                 }
 
@@ -221,11 +221,11 @@ impl Chunk {
                     let captures_with = packed_count & 0b1 == 1;
                     let count = packed_count >> 1;
 
-                    write!(writer, "Op{:?}(BP @ {}, ", op, bp_idx)?;
+                    write!(writer, "Op{op:?}(BP @ {bp_idx}, ")?;
                     if captures_with {
                         write!(writer, "captures with, ")?;
                     }
-                    writeln!(writer, "{} upvalues)", count)?;
+                    writeln!(writer, "{count} upvalues)")?;
 
                     for _ in 0..count {
                         let (_, size) = self.read_uvarint(cidx);
@@ -234,7 +234,7 @@ impl Chunk {
 
                     Ok(cidx - idx.0)
                 }
-                _ => panic!("Snix bug: don't know how to format argument for Op{:?}", op),
+                _ => panic!("Snix bug: don't know how to format argument for Op{op:?}"),
             },
         }
     }

snix/eval/src/compiler/mod.rs

@@ -196,8 +196,7 @@ impl<'source, 'observer> Compiler<'source, 'observer> {
                 let current_dir = std::env::current_dir().map_err(|e| {
                     Error::new(
                         ErrorKind::RelativePathResolution(format!(
-                            "could not determine current directory: {}",
+                            "could not determine current directory: {e}"
-                            e
                         )),
                         file.span,
                         source.clone(),
@@ -1527,15 +1526,15 @@ fn compile_src_builtin(
     let parsed = rnix::ast::Root::parse(code);
 
     if !parsed.errors().is_empty() {
-        let mut out = format!("BUG: code for source-builtin '{}' had parser errors", name);
+        let mut out = format!("BUG: code for source-builtin '{name}' had parser errors");
         for error in parsed.errors() {
-            writeln!(out, "{}", error).unwrap();
+            writeln!(out, "{error}").unwrap();
         }
 
         panic!("{}", out);
     }
 
-    let file = source.add_file(format!("<src-builtins/{}.nix>", name), code.to_string());
+    let file = source.add_file(format!("<src-builtins/{name}.nix>"), code.to_string());
     let weak = weak.clone();
 
     Value::Thunk(Thunk::new_suspended_native(Box::new(move || {
@@ -1555,7 +1554,7 @@ fn compile_src_builtin(
 
         if !result.errors.is_empty() {
             return Err(ErrorKind::ImportCompilerError {
-                path: format!("src-builtins/{}.nix", name).into(),
+                path: format!("src-builtins/{name}.nix").into(),
                 errors: result.errors,
             });
         }

snix/eval/src/errors.rs

@@ -253,7 +253,7 @@ to a missing value in the attribute set(s) included via `with`."#
             let mut disp = format!("Snix bug: {}", .msg);
 
             if let Some(metadata) = .metadata {
-                disp.push_str(&format!("; metadata: {:?}", metadata));
+                disp.push_str(&format!("; metadata: {metadata:?}"));
             }
 
             disp
@@ -588,10 +588,7 @@ fn spans_for_parse_errors(file: &File, errors: &[rnix::parser::ParseError]) -> V
 
                 rnix::parser::ParseError::DuplicatedArgs(range, name) => (
                     range.span_for(file),
-                    format!(
+                    format!("the function argument pattern '{name}' was bound more than once"),
-                        "the function argument pattern '{}' was bound more than once",
-                        name
-                    ),
                 ),
 
                 rnix::parser::ParseError::RecursionLimitExceeded => (
@@ -843,7 +840,7 @@ impl Error {
 
         for ctx in &self.contexts {
             spans.push(SpanLabel {
-                label: Some(format!("while {}", ctx)),
+                label: Some(format!("while {ctx}")),
                 span: self.span,
                 style: SpanStyle::Secondary,
             });

snix/eval/src/io.rs

@@ -44,7 +44,7 @@ impl std::fmt::Display for FileType {
             FileType::Unknown => "unknown",
         };
 
-        write!(f, "{}", type_as_str)
+        write!(f, "{type_as_str}")
     }
 }
 

snix/eval/src/observer.rs

@@ -182,7 +182,7 @@ impl<W: Write> TracingObserver<W> {
             }
 
             // For other value types, defer to the standard value printer.
-            _ => write!(&mut self.writer, "{} ", val),
+            _ => write!(&mut self.writer, "{val} "),
         };
     }
 
@@ -222,7 +222,7 @@ impl<W: Write> RuntimeObserver for TracingObserver<W> {
         };
 
         if let Some(name) = &lambda.name {
-            let _ = write!(&mut self.writer, "'{}' ", name);
+            let _ = write!(&mut self.writer, "'{name}' ");
         }
 
         let _ = writeln!(
@@ -235,13 +235,13 @@ impl<W: Write> RuntimeObserver for TracingObserver<W> {
     /// Called when the runtime exits a call frame.
     fn observe_exit_call_frame(&mut self, frame_at: usize, stack: &[Value]) {
         self.maybe_write_time();
-        let _ = write!(&mut self.writer, "=== exiting frame {} ===\t ", frame_at);
+        let _ = write!(&mut self.writer, "=== exiting frame {frame_at} ===\t ");
         self.write_stack(stack);
     }
 
     fn observe_suspend_call_frame(&mut self, frame_at: usize, stack: &[Value]) {
         self.maybe_write_time();
-        let _ = write!(&mut self.writer, "=== suspending frame {} ===\t", frame_at);
+        let _ = write!(&mut self.writer, "=== suspending frame {frame_at} ===\t");
 
         self.write_stack(stack);
     }
@@ -250,8 +250,7 @@ impl<W: Write> RuntimeObserver for TracingObserver<W> {
         self.maybe_write_time();
         let _ = write!(
             &mut self.writer,
-            "=== entering generator frame '{}' [{}] ===\t",
+            "=== entering generator frame '{name}' [{frame_at}] ===\t",
-            name, frame_at,
         );
 
         self.write_stack(stack);
@@ -261,8 +260,7 @@ impl<W: Write> RuntimeObserver for TracingObserver<W> {
         self.maybe_write_time();
         let _ = write!(
             &mut self.writer,
-            "=== exiting generator '{}' [{}] ===\t",
+            "=== exiting generator '{name}' [{frame_at}] ===\t"
-            name, frame_at
         );
 
         self.write_stack(stack);
@@ -272,8 +270,7 @@ impl<W: Write> RuntimeObserver for TracingObserver<W> {
         self.maybe_write_time();
         let _ = write!(
             &mut self.writer,
-            "=== suspending generator '{}' [{}] ===\t",
+            "=== suspending generator '{name}' [{frame_at}] ===\t"
-            name, frame_at
         );
 
         self.write_stack(stack);
@@ -283,19 +280,18 @@ impl<W: Write> RuntimeObserver for TracingObserver<W> {
         self.maybe_write_time();
         let _ = writeln!(
             &mut self.writer,
-            "=== generator '{}' requested {} ===",
+            "=== generator '{name}' requested {msg} ==="
-            name, msg
         );
     }
 
     fn observe_enter_builtin(&mut self, name: &'static str) {
         self.maybe_write_time();
-        let _ = writeln!(&mut self.writer, "=== entering builtin {} ===", name);
+        let _ = writeln!(&mut self.writer, "=== entering builtin {name} ===");
     }
 
     fn observe_exit_builtin(&mut self, name: &'static str, stack: &[Value]) {
         self.maybe_write_time();
-        let _ = write!(&mut self.writer, "=== exiting builtin {} ===\t", name);
+        let _ = write!(&mut self.writer, "=== exiting builtin {name} ===\t");
         self.write_stack(stack);
     }
 

snix/eval/src/value/attrs/tests.rs

@@ -50,10 +50,7 @@ fn test_kv_attrs() {
             if name.to_str().unwrap() == meaning_val.to_str().unwrap()
                 || value.to_str().unwrap() == forty_two_val.to_str().unwrap() => {}
 
-        _ => panic!(
+        _ => panic!("K/V attribute set should use optimised representation, but got {kv_attrs:?}"),
-            "K/V attribute set should use optimised representation, but got {:?}",
-            kv_attrs
-        ),
     }
 }
 

snix/eval/src/value/mod.rs

@@ -410,7 +410,7 @@ impl Value {
                 (Value::Float(f), CoercionKind { strong: true, .. }) => {
                     // contrary to normal Display, coercing a float to a string will
                     // result in unconditional 6 decimal places
-                    Ok(format!("{:.6}", f).into())
+                    Ok(format!("{f:.6}").into())
                 }
 
                 // Lists are coerced by coercing their elements and interspersing spaces
@@ -842,18 +842,18 @@ impl Value {
     pub fn explain(&self) -> String {
         match self {
             Value::Null => "the 'null' value".into(),
-            Value::Bool(b) => format!("the boolean value '{}'", b),
+            Value::Bool(b) => format!("the boolean value '{b}'"),
-            Value::Integer(i) => format!("the integer '{}'", i),
+            Value::Integer(i) => format!("the integer '{i}'"),
-            Value::Float(f) => format!("the float '{}'", f),
+            Value::Float(f) => format!("the float '{f}'"),
-            Value::String(s) if s.has_context() => format!("the contextful string '{}'", s),
+            Value::String(s) if s.has_context() => format!("the contextful string '{s}'"),
-            Value::String(s) => format!("the contextless string '{}'", s),
+            Value::String(s) => format!("the contextless string '{s}'"),
             Value::Path(p) => format!("the path '{}'", p.to_string_lossy()),
             Value::Attrs(attrs) => format!("a {}-item attribute set", attrs.len()),
             Value::List(list) => format!("a {}-item list", list.len()),
 
             Value::Closure(f) => {
                 if let Some(name) = &f.lambda.name {
-                    format!("the user-defined Nix function '{}'", name)
+                    format!("the user-defined Nix function '{name}'")
                 } else {
                     "a user-defined Nix function".to_string()
                 }
@@ -977,7 +977,7 @@ impl TotalDisplay for Value {
             Value::Null => f.write_str("null"),
             Value::Bool(true) => f.write_str("true"),
             Value::Bool(false) => f.write_str("false"),
-            Value::Integer(num) => write!(f, "{}", num),
+            Value::Integer(num) => write!(f, "{num}"),
             Value::String(s) => s.fmt(f),
             Value::Path(p) => p.display().fmt(f),
             Value::Attrs(attrs) => attrs.total_fmt(f, set),

snix/eval/src/value/string/mod.rs

@@ -656,13 +656,13 @@ impl NixString {
                 if is_valid_nix_identifier(&escaped) && !is_keyword(&escaped) {
                     escaped
                 } else {
-                    Cow::Owned(format!("\"{}\"", escaped))
+                    Cow::Owned(format!("\"{escaped}\""))
                 }
             }
 
             // An owned string has escapes, and needs the outer quotes
             // for display.
-            Cow::Owned(s) => Cow::Owned(format!("\"{}\"", s)),
+            Cow::Owned(s) => Cow::Owned(format!("\"{s}\"")),
         }
     }
 

snix/eval/src/value/thunk.rs

@@ -87,7 +87,7 @@ enum ThunkRepr {
 impl ThunkRepr {
     fn debug_repr(&self) -> String {
         match self {
-            ThunkRepr::Evaluated(v) => format!("thunk(val|{})", v),
+            ThunkRepr::Evaluated(v) => format!("thunk(val|{v})"),
             ThunkRepr::Blackhole { .. } => "thunk(blackhole)".to_string(),
             ThunkRepr::Native(_) => "thunk(native)".to_string(),
             ThunkRepr::Suspended { lambda, .. } => format!("thunk({:p})", *lambda),

snix/eval/src/vm/generators.rs

@@ -155,7 +155,7 @@ impl Display for VMRequest {
                 if *import_paths { "" } else { "non_" },
                 v.type_of()
             ),
-            VMRequest::Call(v) => write!(f, "call({})", v),
+            VMRequest::Call(v) => write!(f, "call({v})"),
             VMRequest::EnterLambda { lambda, .. } => {
                 write!(f, "enter_lambda({:p})", *lambda)
             }
@@ -208,12 +208,12 @@ impl Display for VMResponse {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
             VMResponse::Empty => write!(f, "empty"),
-            VMResponse::Value(v) => write!(f, "value({})", v),
+            VMResponse::Value(v) => write!(f, "value({v})"),
             VMResponse::Path(p) => write!(f, "path({})", p.to_string_lossy()),
             VMResponse::Directory(d) => write!(f, "dir(len = {})", d.len()),
             VMResponse::Span(_) => write!(f, "span"),
             VMResponse::Reader(_) => write!(f, "reader"),
-            VMResponse::FileType(t) => write!(f, "file_type({})", t),
+            VMResponse::FileType(t) => write!(f, "file_type({t})"),
         }
     }
 }
@@ -527,10 +527,7 @@ pub type GenCo = Co<VMRequest, VMResponse>;
 pub async fn request_stack_push(co: &GenCo, val: Value) {
     match co.yield_(VMRequest::StackPush(val)).await {
         VMResponse::Empty => {}
-        msg => panic!(
+        msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-            "Snix bug: VM responded with incorrect generator message: {}",
-            msg
-        ),
     }
 }
 
@@ -539,10 +536,7 @@ pub async fn request_stack_push(co: &GenCo, val: Value) {
 pub async fn request_stack_pop(co: &GenCo) -> Value {
     match co.yield_(VMRequest::StackPop).await {
         VMResponse::Value(value) => value,
-        msg => panic!(
+        msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-            "Snix bug: VM responded with incorrect generator message: {}",
-            msg
-        ),
     }
 }
 
@@ -551,10 +545,7 @@ pub async fn request_force(co: &GenCo, val: Value) -> Value {
     if let Value::Thunk(_) = val {
         match co.yield_(VMRequest::ForceValue(val)).await {
             VMResponse::Value(value) => value,
-            msg => panic!(
+            msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-                "Snix bug: VM responded with incorrect generator message: {}",
-                msg
-            ),
         }
     } else {
         val
@@ -566,10 +557,7 @@ pub(crate) async fn request_try_force(co: &GenCo, val: Value) -> Value {
     if let Value::Thunk(_) = val {
         match co.yield_(VMRequest::TryForce(val)).await {
             VMResponse::Value(value) => value,
-            msg => panic!(
+            msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-                "Snix bug: VM responded with incorrect generator message: {}",
-                msg
-            ),
         }
     } else {
         val
@@ -582,10 +570,7 @@ pub async fn request_call(co: &GenCo, val: Value) -> Value {
     let val = request_force(co, val).await;
     match co.yield_(VMRequest::Call(val)).await {
         VMResponse::Value(value) => value,
-        msg => panic!(
+        msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-            "Snix bug: VM responded with incorrect generator message: {}",
-            msg
-        ),
     }
 }
 
@@ -624,10 +609,7 @@ pub async fn request_string_coerce(
             VMResponse::Value(value) => Ok(value
                 .to_contextful_str()
                 .expect("coerce_to_string always returns a string")),
-            msg => panic!(
+            msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-                "Snix bug: VM responded with incorrect generator message: {}",
-                msg
-            ),
         },
     }
 }
@@ -636,10 +618,7 @@ pub async fn request_string_coerce(
 pub async fn request_deep_force(co: &GenCo, val: Value) -> Value {
     match co.yield_(VMRequest::DeepForceValue(val)).await {
         VMResponse::Value(value) => value,
-        msg => panic!(
+        msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-            "Snix bug: VM responded with incorrect generator message: {}",
-            msg
-        ),
     }
 }
 
@@ -656,10 +635,7 @@ pub(crate) async fn check_equality(
     {
         VMResponse::Value(Value::Bool(b)) => Ok(Ok(b)),
         VMResponse::Value(Value::Catchable(cek)) => Ok(Err(*cek)),
-        msg => panic!(
+        msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-            "Snix bug: VM responded with incorrect generator message: {}",
-            msg
-        ),
     }
 }
 
@@ -667,10 +643,7 @@ pub(crate) async fn check_equality(
 pub(crate) async fn emit_warning(co: &GenCo, warning: EvalWarning) {
     match co.yield_(VMRequest::EmitWarning(warning)).await {
         VMResponse::Empty => {}
-        msg => panic!(
+        msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-            "Snix bug: VM responded with incorrect generator message: {}",
-            msg
-        ),
     }
 }
 
@@ -678,10 +651,7 @@ pub(crate) async fn emit_warning(co: &GenCo, warning: EvalWarning) {
 pub async fn emit_warning_kind(co: &GenCo, kind: WarningKind) {
     match co.yield_(VMRequest::EmitWarningKind(kind)).await {
         VMResponse::Empty => {}
-        msg => panic!(
+        msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-            "Snix bug: VM responded with incorrect generator message: {}",
-            msg
-        ),
     }
 }
 
@@ -700,10 +670,7 @@ pub(crate) async fn request_enter_lambda(
 
     match co.yield_(msg).await {
         VMResponse::Value(value) => value,
-        msg => panic!(
+        msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-            "Snix bug: VM responded with incorrect generator message: {}",
-            msg
-        ),
     }
 }
 
@@ -712,10 +679,7 @@ pub(crate) async fn request_import_cache_lookup(co: &GenCo, path: PathBuf) -> Op
     match co.yield_(VMRequest::ImportCacheLookup(path)).await {
         VMResponse::Value(value) => Some(value),
         VMResponse::Empty => None,
-        msg => panic!(
+        msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-            "Snix bug: VM responded with incorrect generator message: {}",
-            msg
-        ),
     }
 }
 
@@ -723,10 +687,7 @@ pub(crate) async fn request_import_cache_lookup(co: &GenCo, path: PathBuf) -> Op
 pub(crate) async fn request_import_cache_put(co: &GenCo, path: PathBuf, value: Value) {
     match co.yield_(VMRequest::ImportCachePut(path, value)).await {
         VMResponse::Empty => {}
-        msg => panic!(
+        msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-            "Snix bug: VM responded with incorrect generator message: {}",
-            msg
-        ),
     }
 }
 
@@ -734,10 +695,7 @@ pub(crate) async fn request_import_cache_put(co: &GenCo, path: PathBuf, value: V
 pub(crate) async fn request_path_import(co: &GenCo, path: PathBuf) -> PathBuf {
     match co.yield_(VMRequest::PathImport(path)).await {
         VMResponse::Path(path) => path,
-        msg => panic!(
+        msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-            "Snix bug: VM responded with incorrect generator message: {}",
-            msg
-        ),
     }
 }
 
@@ -745,10 +703,7 @@ pub(crate) async fn request_path_import(co: &GenCo, path: PathBuf) -> PathBuf {
 pub async fn request_open_file(co: &GenCo, path: PathBuf) -> Box<dyn std::io::Read> {
     match co.yield_(VMRequest::OpenFile(path)).await {
         VMResponse::Reader(value) => value,
-        msg => panic!(
+        msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-            "Snix bug: VM responded with incorrect generator message: {}",
-            msg
-        ),
     }
 }
 
@@ -756,10 +711,7 @@ pub async fn request_open_file(co: &GenCo, path: PathBuf) -> Box<dyn std::io::Re
 pub(crate) async fn request_path_exists(co: &GenCo, path: PathBuf) -> Value {
     match co.yield_(VMRequest::PathExists(path)).await {
         VMResponse::Value(value) => value,
-        msg => panic!(
+        msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-            "Snix bug: VM responded with incorrect generator message: {}",
-            msg
-        ),
     }
 }
 
@@ -767,20 +719,14 @@ pub(crate) async fn request_path_exists(co: &GenCo, path: PathBuf) -> Value {
 pub(crate) async fn request_read_dir(co: &GenCo, path: PathBuf) -> Vec<(bytes::Bytes, FileType)> {
     match co.yield_(VMRequest::ReadDir(path)).await {
         VMResponse::Directory(dir) => dir,
-        msg => panic!(
+        msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-            "Snix bug: VM responded with incorrect generator message: {}",
-            msg
-        ),
     }
 }
 
 pub(crate) async fn request_span(co: &GenCo) -> Span {
     match co.yield_(VMRequest::Span).await {
         VMResponse::Span(span) => span,
-        msg => panic!(
+        msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-            "Snix bug: VM responded with incorrect generator message: {}",
-            msg
-        ),
     }
 }
 
@@ -788,10 +734,7 @@ pub(crate) async fn request_span(co: &GenCo) -> Span {
 pub(crate) async fn request_read_file_type(co: &GenCo, path: PathBuf) -> FileType {
     match co.yield_(VMRequest::ReadFileType(path)).await {
         VMResponse::FileType(file_type) => file_type,
-        msg => panic!(
+        msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-            "Snix bug: VM responded with incorrect generator message: {}",
-            msg
-        ),
     }
 }
 

snix/eval/src/vm/mod.rs

@@ -1234,10 +1234,7 @@ async fn resolve_with(
     async fn fetch_forced_with(co: &GenCo, idx: usize) -> Value {
         match co.yield_(VMRequest::WithValue(idx)).await {
             VMResponse::Value(value) => value,
-            msg => panic!(
+            msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-                "Snix bug: VM responded with incorrect generator message: {}",
-                msg
-            ),
         }
     }
 
@@ -1245,10 +1242,7 @@ async fn resolve_with(
     async fn fetch_captured_with(co: &GenCo, idx: usize) -> Value {
         match co.yield_(VMRequest::CapturedWithValue(idx)).await {
             VMResponse::Value(value) => value,
-            msg => panic!(
+            msg => panic!("Snix bug: VM responded with incorrect generator message: {msg}"),
-                "Snix bug: VM responded with incorrect generator message: {}",
-                msg
-            ),
         }
     }
 

snix/eval/src/warnings.rs

@@ -92,7 +92,7 @@ impl EvalWarning {
             }
 
             WarningKind::ShadowedGlobal(name) => {
-                format!("declared variable '{}' shadows a built-in global!", name)
+                format!("declared variable '{name}' shadows a built-in global!")
             }
 
             WarningKind::DeprecatedLegacyLet => {
@@ -100,11 +100,11 @@ impl EvalWarning {
             }
 
             WarningKind::InvalidNixPath(ref err) => {
-                format!("invalid NIX_PATH resulted in a parse error: {}", err)
+                format!("invalid NIX_PATH resulted in a parse error: {err}")
             }
 
             WarningKind::UselessBoolOperation(msg) => {
-                format!("useless operation on boolean: {}", msg)
+                format!("useless operation on boolean: {msg}")
             }
 
             WarningKind::DeadCode => "this code will never be executed".to_string(),
@@ -113,14 +113,13 @@ impl EvalWarning {
 
             WarningKind::EmptyLet => "this `let`-expression contains no bindings".to_string(),
 
-            WarningKind::ShadowedOutput(ref out) => format!(
+            WarningKind::ShadowedOutput(ref out) => {
-                "this derivation's environment shadows the output name {}",
+                format!("this derivation's environment shadows the output name {out}")
-                out
+            }
-            ),
             WarningKind::SRIHashWrongPadding => "SRI hash has wrong padding".to_string(),
 
             WarningKind::NotImplemented(what) => {
-                format!("feature not yet implemented in snix: {}", what)
+                format!("feature not yet implemented in snix: {what}")
             }
         }
     }

snix/glue/src/builtins/derivation.rs

@@ -43,8 +43,7 @@ fn populate_inputs(drv: &mut Derivation, full_context: NixContext, known_paths:
                 #[cfg(debug_assertions)]
                 assert!(
                     _rest.iter().next().is_none(),
-                    "Extra path not empty for {}",
+                    "Extra path not empty for {derivation_str}"
-                    derivation_str
                 );
 
                 match drv.input_derivations.entry(derivation.clone()) {
@@ -65,8 +64,7 @@ fn populate_inputs(drv: &mut Derivation, full_context: NixContext, known_paths:
                 #[cfg(debug_assertions)]
                 assert!(
                     _rest.iter().next().is_none(),
-                    "Extra path not empty for {}",
+                    "Extra path not empty for {drv_path}"
-                    drv_path
                 );
 
                 // We need to know all the outputs *names* of that derivation.
@@ -160,7 +158,7 @@ fn handle_fixed_output(
         // Peek at hash_str once more.
         // If it was a SRI hash, but is not using the correct length, this means
         // the padding was wrong. Emit a warning in that case.
-        let sri_prefix = format!("{}-", algo);
+        let sri_prefix = format!("{algo}-");
         if let Some(rest) = hash_str.strip_prefix(&sri_prefix) {
             if data_encoding::BASE64.encode_len(algo.digest_length()) != rest.len() {
                 return Ok(Some(WarningKind::SRIHashWrongPadding));
@@ -475,7 +473,7 @@ pub(crate) mod derivation_builtins {
             &drv.hash_derivation_modulo(|drv_path| {
                 *known_paths
                     .get_hash_derivation_modulo(&drv_path.to_owned())
-                    .unwrap_or_else(|| panic!("{} not found", drv_path))
+                    .unwrap_or_else(|| panic!("{drv_path} not found"))
             }),
         )
         .map_err(DerivationError::InvalidDerivation)?;

snix/glue/src/builtins/import.rs

@@ -99,7 +99,7 @@ async fn filtered_ingest(
             .await
             .map_err(|e| ErrorKind::IO {
                 path: Some(path.to_path_buf()),
-                error: Rc::new(std::io::Error::new(std::io::ErrorKind::Other, e)),
+                error: Rc::new(std::io::Error::other(e)),
             })
     })
 }

snix/glue/src/builtins/mod.rs

@@ -117,7 +117,7 @@ mod tests {
             snix_eval::Value::String(s) => {
                 assert_eq!(*s, "/nix/store/xpcvxsx5sw4rbq666blz6sxqlmsqphmr-foo",);
             }
-            _ => panic!("unexpected value type: {:?}", value),
+            _ => panic!("unexpected value type: {value:?}"),
         }
     }
 
@@ -204,7 +204,7 @@ mod tests {
             snix_eval::Value::String(s) => {
                 assert_eq!(*s, expected_path);
             }
-            _ => panic!("unexpected value type: {:?}", value),
+            _ => panic!("unexpected value type: {value:?}"),
         }
     }
 
@@ -236,7 +236,7 @@ mod tests {
             snix_eval::Value::Bool(v) => {
                 assert!(v);
             }
-            _ => panic!("unexpected value type: {:?}", value),
+            _ => panic!("unexpected value type: {value:?}"),
         }
     }
 
@@ -254,7 +254,7 @@ mod tests {
             snix_eval::Value::Bool(v) => {
                 assert!(v);
             }
-            _ => panic!("unexpected value type: {:?}", value),
+            _ => panic!("unexpected value type: {value:?}"),
         }
     }
 
@@ -276,7 +276,7 @@ mod tests {
             snix_eval::Value::Bool(v) => {
                 assert!(v);
             }
-            _ => panic!("unexpected value type: {:?}", value),
+            _ => panic!("unexpected value type: {value:?}"),
         }
     }
 
@@ -297,7 +297,7 @@ mod tests {
             snix_eval::Value::Bool(v) => {
                 assert!(v);
             }
-            _ => panic!("unexpected value type: {:?}", value),
+            _ => panic!("unexpected value type: {value:?}"),
         }
     }
 
@@ -330,7 +330,7 @@ mod tests {
                 assert_eq!(*s, expected_drvpath);
             }
 
-            _ => panic!("unexpected value type: {:?}", value),
+            _ => panic!("unexpected value type: {value:?}"),
         };
     }
 
@@ -362,7 +362,7 @@ mod tests {
             snix_eval::Value::String(s) => {
                 assert_eq!(*s, expected_path);
             }
-            _ => panic!("unexpected value type: {:?}", value),
+            _ => panic!("unexpected value type: {value:?}"),
         }
 
         assert!(
@@ -536,7 +536,7 @@ mod tests {
             snix_eval::Value::String(s) => {
                 assert_eq!(expected_outpath, s.as_bstr());
             }
-            _ => panic!("unexpected value type: {:?}", value),
+            _ => panic!("unexpected value type: {value:?}"),
         }
 
         assert!(eval_result.errors.is_empty(), "errors should be empty");
@@ -580,7 +580,7 @@ mod tests {
                         s.as_bstr()
                     );
                 }
-                v => panic!("unexpected value type: {:?}", v),
+                v => panic!("unexpected value type: {v:?}"),
             }
         } else {
             assert!(value.is_none(), "unexpected success on illegal store paths");
@@ -626,7 +626,7 @@ mod tests {
                         s.as_bstr()
                     );
                 }
-                v => panic!("unexpected value type: {:?}", v),
+                v => panic!("unexpected value type: {v:?}"),
             }
         } else {
             assert!(value.is_none(), "unexpected success on illegal store paths");
@@ -714,7 +714,7 @@ mod tests {
             snix_eval::Value::String(s) => {
                 assert_eq!(expected_outpath, s.as_bstr());
             }
-            _ => panic!("unexpected value type: {:?}", value),
+            _ => panic!("unexpected value type: {value:?}"),
         }
 
         assert!(eval_result.errors.is_empty(), "errors should be empty");

snix/glue/src/fetchers/mod.rs

@@ -116,7 +116,7 @@ impl std::fmt::Debug for Fetch {
                         NixHash::Sha256(*exp_nar_sha256)
                     )
                 } else {
-                    write!(f, "Tarball [url: {}, exp_hash: None]", url)
+                    write!(f, "Tarball [url: {url}, exp_hash: None]")
                 }
             }
             Fetch::NAR { url, hash } => {

snix/glue/src/known_paths.rs

@@ -78,7 +78,7 @@ impl KnownPaths {
         // compute the hash derivation modulo
         let hash_derivation_modulo = drv.hash_derivation_modulo(|drv_path| {
             self.get_hash_derivation_modulo(&drv_path.to_owned())
-                .unwrap_or_else(|| panic!("{} not found", drv_path))
+                .unwrap_or_else(|| panic!("{drv_path} not found"))
                 .to_owned()
         });
 

snix/glue/src/lib.rs

@@ -23,7 +23,7 @@ pub fn configure_nix_path<'co, 'ro, 'env, IO>(
     eval_builder.nix_path(
         nix_search_path
             .as_ref()
-            .map(|p| format!("nix=/__corepkgs__:{}", p))
+            .map(|p| format!("nix=/__corepkgs__:{p}"))
             .or_else(|| Some("nix=/__corepkgs__".to_string())),
     )
 }

snix/glue/src/snix_build.rs

@@ -258,7 +258,7 @@ fn handle_pass_as_file(
 /// The filepath is `/build/.attrs-${nixbase32(sha256(key))`.
 fn calculate_pass_as_file_env(k: &str) -> (String, String) {
     (
-        format!("{}Path", k),
+        format!("{k}Path"),
         format!(
             "/build/.attr-{}",
             nixbase32::encode(&Sha256::new_with_prefix(k).finalize())

snix/glue/src/snix_store_io.rs

@@ -223,7 +223,7 @@ impl SnixStoreIO {
                             .as_ref()
                             .do_build(build_request)
                             .await
-                            .map_err(|e| std::io::Error::new(io::ErrorKind::Other, e))?;
+                            .map_err(std::io::Error::other)?;
 
                         let mut out_path_info: Option<PathInfo> = None;
 
@@ -256,8 +256,7 @@ impl SnixStoreIO {
                                             all_possible_refs
                                                 .get(*idx as usize)
                                                 .map(|it| (*it).clone())
-                                                .ok_or(std::io::Error::new(
+                                                .ok_or(std::io::Error::other(
-                                                    std::io::ErrorKind::Other,
                                                     "invalid build response",
                                                 ))
                                         })
@@ -289,7 +288,7 @@ impl SnixStoreIO {
                             self.path_info_service
                                 .put(path_info.clone())
                                 .await
-                                .map_err(|e| std::io::Error::new(io::ErrorKind::Other, e))?;
+                                .map_err(std::io::Error::other)?;
 
                             if store_path == &output_path {
                                 out_path_info = Some(path_info);
@@ -309,7 +308,7 @@ impl SnixStoreIO {
         Ok(
             directoryservice::descend_to(&self.directory_service, path_info.node.clone(), sub_path)
                 .await
-                .map_err(|e| std::io::Error::new(io::ErrorKind::Other, e))?
+                .map_err(std::io::Error::other)?
                 .map(|node| {
                     path_info.node = node;
                     path_info
@@ -361,7 +360,7 @@ impl EvalIO for SnixStoreIO {
                         // This would normally be a io::ErrorKind::IsADirectory (still unstable)
                         Err(io::Error::new(
                             io::ErrorKind::Unsupported,
-                            format!("tried to open directory at {:?}", path),
+                            format!("tried to open directory at {path:?}"),
                         ))
                     }
                     Node::File { digest, .. } => {
@@ -558,7 +557,7 @@ mod tests {
         let value = result.value.expect("must be some");
         match value {
             snix_eval::Value::String(s) => Some(s.to_str_lossy().into_owned()),
-            _ => panic!("unexpected value type: {:?}", value),
+            _ => panic!("unexpected value type: {value:?}"),
         }
     }
 
@@ -625,7 +624,7 @@ mod tests {
             snix_eval::Value::String(s) => {
                 assert_eq!(*s, "/deep/thought");
             }
-            _ => panic!("unexpected value type: {:?}", value),
+            _ => panic!("unexpected value type: {value:?}"),
         }
     }
 }

snix/nar-bridge/src/lib.rs

@@ -83,9 +83,6 @@ async fn four_o_four() -> Result<(), StatusCode> {
 async fn nix_cache_info(priority: u64) -> impl IntoResponse {
     (
         [("Content-Type", nix_http::MIME_TYPE_CACHE_INFO)],
-        format!(
+        format!("StoreDir: /nix/store\nWantMassQuery: 1\nPriority: {priority}\n"),
-            "StoreDir: /nix/store\nWantMassQuery: 1\nPriority: {}\n",
-            priority
-        ),
     )
 }

snix/nix-compat-derive/src/internal/attrs.rs

@@ -51,7 +51,7 @@ impl Field {
                     }
                 } else {
                     let path = meta.path.to_token_stream().to_string();
-                    return Err(meta.error(format_args!("unknown nix field attribute '{}'", path)));
+                    return Err(meta.error(format_args!("unknown nix field attribute '{path}'")));
                 }
                 Ok(())
             }) {
@@ -86,9 +86,7 @@ impl Variant {
                     }
                 } else {
                     let path = meta.path.to_token_stream().to_string();
-                    return Err(
+                    return Err(meta.error(format_args!("unknown nix variant attribute '{path}'")));
-                        meta.error(format_args!("unknown nix variant attribute '{}'", path))
-                    );
                 }
                 Ok(())
             }) {
@@ -149,9 +147,7 @@ impl Container {
                     crate_path = parse_lit(ctx, &meta, CRATE)?;
                 } else {
                     let path = meta.path.to_token_stream().to_string();
-                    return Err(
+                    return Err(meta.error(format_args!("unknown nix variant attribute '{path}'")));
-                        meta.error(format_args!("unknown nix variant attribute '{}'", path))
-                    );
                 }
                 Ok(())
             }) {
@@ -190,7 +186,7 @@ pub fn get_lit_str(
     } else {
         ctx.error_spanned(
             expr,
-            format_args!("expected nix attribute {} to be string", attr),
+            format_args!("expected nix attribute {attr} to be string"),
         );
         Ok(None)
     }

snix/nix-compat/src/bin/drvfmt.rs

@@ -42,6 +42,6 @@ fn main() {
                     .expect("unable to serialize")
             );
         }
-        Err(e) => eprintln!("unable to parse derivation: {:#?}", e),
+        Err(e) => eprintln!("unable to parse derivation: {e:#?}"),
     }
 }

snix/nix-compat/src/derivation/mod.rs

@@ -133,7 +133,7 @@ impl Derivation {
         name: &str,
     ) -> Result<StorePath<String>, DerivationError> {
         // append .drv to the name
-        let name = format!("{}.drv", name);
+        let name = format!("{name}.drv");
 
         // collect the list of paths from input_sources and input_derivations
         // into a (sorted, guaranteed by BTreeSet) list of references
@@ -362,6 +362,6 @@ fn ca_kind_prefix(ca_hash: &CAHash) -> &'static str {
     match ca_hash {
         CAHash::Flat(_) => "",
         CAHash::Nar(_) => "r:",
-        _ => panic!("invalid ca hash in derivation context: {:?}", ca_hash),
+        _ => panic!("invalid ca hash in derivation context: {ca_hash:?}"),
     }
 }

snix/nix-compat/src/derivation/tests/mod.rs

@@ -151,7 +151,7 @@ fn from_aterm_bytes_trailer() {
 )]
 #[case::unicode("unicode", "52a9id8hx688hvlnz4d1n25ml1jdykz0-unicode.drv")]
 fn derivation_path(#[case] name: &str, #[case] expected_path: &str) {
-    let json_bytes = fs::read(format!("{}/ok/{}.json", RESOURCES_PATHS, expected_path))
+    let json_bytes = fs::read(format!("{RESOURCES_PATHS}/ok/{expected_path}.json"))
         .expect("unable to read JSON");
     let derivation: Derivation =
         serde_json::from_slice(&json_bytes).expect("JSON was not well-formatted");
@@ -194,7 +194,7 @@ fn derivation_without_output_paths(derivation: &Derivation) -> Derivation {
 fn hash_derivation_modulo_fixed(#[case] drv_path: &str, #[case] expected_digest: [u8; 32]) {
     // read in the fixture
     let json_bytes =
-        fs::read(format!("{}/ok/{}.json", RESOURCES_PATHS, drv_path)).expect("unable to read JSON");
+        fs::read(format!("{RESOURCES_PATHS}/ok/{drv_path}.json")).expect("unable to read JSON");
     let drv: Derivation = serde_json::from_slice(&json_bytes).expect("must deserialize");
 
     let actual = drv.hash_derivation_modulo(|_| panic!("must not be called"));
@@ -220,7 +220,7 @@ fn hash_derivation_modulo_fixed(#[case] drv_path: &str, #[case] expected_digest:
 fn output_paths(#[case] name: &str, #[case] drv_path_str: &str) {
     // read in the derivation
     let expected_derivation = Derivation::from_aterm_bytes(
-        &fs::read(format!("{}/ok/{}", RESOURCES_PATHS, drv_path_str)).expect("unable to read .drv"),
+        &fs::read(format!("{RESOURCES_PATHS}/ok/{drv_path_str}")).expect("unable to read .drv"),
     )
     .expect("must succeed");
 
@@ -410,7 +410,7 @@ fn output_path_construction() {
         "foo",
         &foo_drv.hash_derivation_modulo(|drv_path| {
             if drv_path.to_string() != "0hm2f1psjpcwg8fijsmr4wwxrx59s092-bar.drv" {
-                panic!("lookup called with unexpected drv_path: {}", drv_path);
+                panic!("lookup called with unexpected drv_path: {drv_path}");
             }
             bar_drv_hash_derivation_modulo
         }),

snix/nix-compat/src/flakeref/mod.rs

@@ -590,7 +590,7 @@ impl FlakeRef {
                     _ => unreachable!(),
                 };
 
-                let mut url = Url::parse(&format!("{}://{}/{}", scheme, owner, repo)).unwrap();
+                let mut url = Url::parse(&format!("{scheme}://{owner}/{repo}")).unwrap();
                 if let Some(h) = host {
                     url.set_host(Some(h)).unwrap();
                 }
@@ -609,7 +609,7 @@ impl FlakeRef {
                 url
             }
             FlakeRef::Indirect { id, r#ref, rev } => {
-                let mut url = Url::parse(&format!("indirect://{}", id)).unwrap();
+                let mut url = Url::parse(&format!("indirect://{id}")).unwrap();
                 append_params(&mut url, &[("ref", r#ref.clone()), ("rev", rev.clone())]);
                 url
             }

snix/nix-compat/src/nar/reader/async/test.rs

@@ -290,7 +290,7 @@ async fn must_read_file(name: &'static str, entry: nar::reader::Entry<'_, '_>) {
             assert!(!executable);
             assert_eq!(reader.read(&mut [0]).await.unwrap(), 0);
         }
-        _ => panic!("unexpected type for {}", name),
+        _ => panic!("unexpected type for {name}"),
     }
 }
 
@@ -305,6 +305,6 @@ fn must_be_symlink(
         nar::reader::Node::Symlink { target } => {
             assert_eq!(exp_target.as_bytes(), &target);
         }
-        _ => panic!("unexpected type for {}", name),
+        _ => panic!("unexpected type for {name}"),
     }
 }

snix/nix-compat/src/nar/reader/test.rs

@@ -258,7 +258,7 @@ fn must_read_file(name: &'static str, entry: nar::reader::Entry<'_, '_>) {
             assert!(!executable);
             assert_eq!(reader.read(&mut [0]).unwrap(), 0);
         }
-        _ => panic!("unexpected type for {}", name),
+        _ => panic!("unexpected type for {name}"),
     }
 }
 
@@ -273,6 +273,6 @@ fn must_be_symlink(
         nar::reader::Node::Symlink { target } => {
             assert_eq!(exp_target.as_bytes(), &target);
         }
-        _ => panic!("unexpected type for {}", name),
+        _ => panic!("unexpected type for {name}"),
     }
 }

snix/nix-compat/src/nix_daemon/handler.rs

@@ -357,7 +357,7 @@ mod tests {
             }
             Err(e) => {
                 w.write_value(&STDERR_ERROR).await.unwrap();
-                w.write_value(&NixError::new(format!("{:?}", e)))
+                w.write_value(&NixError::new(format!("{e:?}")))
                     .await
                     .unwrap();
             }

snix/nix-compat/src/nix_daemon/types.rs

@@ -118,7 +118,7 @@ impl NixDeserialize for CAHash {
         let value: Option<String> = reader.try_read_value().await?;
         match value {
             Some(value) => Ok(Some(CAHash::from_nix_hex_str(&value).ok_or_else(|| {
-                R::Error::invalid_data(format!("Invalid cahash {}", value))
+                R::Error::invalid_data(format!("Invalid cahash {value}"))
             })?)),
             None => Ok(None),
         }
@@ -137,7 +137,7 @@ impl NixDeserialize for Option<CAHash> {
                     Ok(None)
                 } else {
                     Ok(Some(Some(CAHash::from_nix_hex_str(&value).ok_or_else(
-                        || R::Error::invalid_data(format!("Invalid cahash {}", value)),
+                        || R::Error::invalid_data(format!("Invalid cahash {value}")),
                     )?)))
                 }
             }

snix/nix-compat/src/nix_daemon/worker_protocol.rs

@@ -168,7 +168,7 @@ where
     if worker_magic_1 != WORKER_MAGIC_1 {
         Err(std::io::Error::new(
             ErrorKind::InvalidData,
-            format!("Incorrect worker magic number received: {}", worker_magic_1),
+            format!("Incorrect worker magic number received: {worker_magic_1}"),
         ))
     } else {
         conn.write_u64_le(WORKER_MAGIC_2).await?;
@@ -182,7 +182,7 @@ where
         if client_version < ProtocolVersion::from_parts(1, 10) {
             return Err(Error::new(
                 ErrorKind::Unsupported,
-                format!("The nix client version {} is too old", client_version),
+                format!("The nix client version {client_version} is too old"),
             ));
         }
         let picked_version = min(PROTOCOL_VERSION, client_version);
@@ -215,7 +215,7 @@ pub async fn read_op<R: AsyncReadExt + Unpin>(r: &mut R) -> std::io::Result<Oper
     Operation::try_from(op_number).map_err(|_| {
         Error::new(
             ErrorKind::InvalidData,
-            format!("Invalid OP number {}", op_number),
+            format!("Invalid OP number {op_number}"),
         )
     })
 }

snix/nix-compat/src/store_path/mod.rs

@@ -202,7 +202,7 @@ where
     /// That is just the string representation, prefixed with the store prefix
     /// ([STORE_DIR_WITH_SLASH]),
     pub fn to_absolute_path(&self) -> String {
-        format!("{}{}", STORE_DIR_WITH_SLASH, self)
+        format!("{STORE_DIR_WITH_SLASH}{self}")
     }
 }
 

snix/nix-compat/src/store_path/utils.rs

@@ -203,7 +203,7 @@ fn make_references_string<S: AsRef<str>, I: IntoIterator<Item = S>>(
 /// The actual placeholder is basically just a SHA256 hash encoded in
 /// cppnix format.
 pub fn hash_placeholder(name: &str) -> String {
-    let digest = Sha256::new_with_prefix(format!("nix-output:{}", name)).finalize();
+    let digest = Sha256::new_with_prefix(format!("nix-output:{name}")).finalize();
 
     format!("/{}", nixbase32::encode(&digest))
 }

snix/nix-compat/src/wire/bytes/reader/mod.rs

@@ -554,7 +554,7 @@ mod tests {
         let payload = &hex!("FF0102030405060708");
         let mut mock = Builder::new()
             .read(&produce_packet_bytes(payload).await[..offset])
-            .read_error(std::io::Error::new(std::io::ErrorKind::Other, "foo"))
+            .read_error(std::io::Error::other("foo"))
             .build();
 
         // Either length reading or data reading can fail, depending on which test case we're in.
@@ -595,7 +595,7 @@ mod tests {
         let payload = &hex!("FF0102030405060708");
         let mock = Builder::new()
             .read(&produce_packet_bytes(payload).await[..offset])
-            .read_error(std::io::Error::new(std::io::ErrorKind::Other, "foo"))
+            .read_error(std::io::Error::other("foo"))
             .build();
         let mut mock = BufReader::new(mock);
 
@@ -631,7 +631,7 @@ mod tests {
         let payload = &hex!("FF0102030405060708");
         let mut mock = Builder::new()
             .read(&produce_packet_bytes(payload).await)
-            .read_error(std::io::Error::new(std::io::ErrorKind::Other, "foo"))
+            .read_error(std::io::Error::other("foo"))
             .build();
 
         let mut r = BytesReader::new(&mut mock, ..MAX_LEN).await.unwrap();
@@ -648,7 +648,7 @@ mod tests {
         let payload = &hex!("FF0102030405060708");
         let mock = Builder::new()
             .read(&produce_packet_bytes(payload).await)
-            .read_error(std::io::Error::new(std::io::ErrorKind::Other, "foo"))
+            .read_error(std::io::Error::other("foo"))
             .build();
         let mut mock = BufReader::new(mock);
 

snix/nix-compat/src/wire/bytes/writer.rs

@@ -477,7 +477,7 @@ mod tests {
 
         let mut mock = Builder::new()
             .write(&1u32.to_le_bytes())
-            .write_error(std::io::Error::new(std::io::ErrorKind::Other, "🍿"))
+            .write_error(std::io::Error::other("🍿"))
             .build();
         let mut w = BytesWriter::new(&mut mock, payload.len() as u64);
 
@@ -492,7 +492,7 @@ mod tests {
 
         let mut mock = Builder::new()
             .write(&1u32.to_le_bytes())
-            .write_error(std::io::Error::new(std::io::ErrorKind::Other, "🍿"))
+            .write_error(std::io::Error::other("🍿"))
             .build();
         let mut w = BytesWriter::new(&mut mock, payload.len() as u64);
 
@@ -508,7 +508,7 @@ mod tests {
         let mut mock = Builder::new()
             .write(&2u64.to_le_bytes())
             .write(&hex!("f0"))
-            .write_error(std::io::Error::new(std::io::ErrorKind::Other, "🍿"))
+            .write_error(std::io::Error::other("🍿"))
             .build();
         let mut w = BytesWriter::new(&mut mock, payload.len() as u64);
 
@@ -526,7 +526,7 @@ mod tests {
             .write(&1u64.to_le_bytes())
             .write(&hex!("f0"))
             .write(&hex!("00"))
-            .write_error(std::io::Error::new(std::io::ErrorKind::Other, "🍿"))
+            .write_error(std::io::Error::other("🍿"))
             .build();
         let mut w = BytesWriter::new(&mut mock, payload.len() as u64);
 

snix/nix-compat/src/wire/de/mod.rs

@@ -24,7 +24,7 @@ pub trait Error: Sized + StdError {
 
     /// Some kind of std::io::Error occured.
     fn io_error(err: std::io::Error) -> Self {
-        Self::custom(format_args!("There was an I/O error {}", err))
+        Self::custom(format_args!("There was an I/O error {err}"))
     }
 
     /// The data read from `NixRead` is invalid.
@@ -41,7 +41,7 @@ pub trait Error: Sized + StdError {
 
 impl Error for io::Error {
     fn custom<T: fmt::Display>(msg: T) -> Self {
-        io::Error::new(io::ErrorKind::Other, msg.to_string())
+        io::Error::other(msg.to_string())
     }
 
     fn io_error(err: std::io::Error) -> Self {

snix/nix-compat/src/wire/ser/mock.rs

@@ -215,7 +215,7 @@ impl Builder {
             Operation::WriteDisplay(_, Err(Error::WrongWrite(op, OperationType::WriteDisplay))) => {
                 self.write_operation_type(*op)
             }
-            s => panic!("Invalid operation {:?}", s),
+            s => panic!("Invalid operation {s:?}"),
         }
     }
 

snix/nix-compat/src/wire/ser/mod.rs

@@ -19,7 +19,7 @@ pub trait Error: Sized + StdError {
     fn custom<T: fmt::Display>(msg: T) -> Self;
 
     fn io_error(err: std::io::Error) -> Self {
-        Self::custom(format_args!("There was an I/O error {}", err))
+        Self::custom(format_args!("There was an I/O error {err}"))
     }
 
     fn unsupported_data<T: fmt::Display>(msg: T) -> Self {
@@ -33,7 +33,7 @@ pub trait Error: Sized + StdError {
 
 impl Error for io::Error {
     fn custom<T: fmt::Display>(msg: T) -> Self {
-        io::Error::new(io::ErrorKind::Other, msg.to_string())
+        io::Error::other(msg.to_string())
     }
 
     fn io_error(err: std::io::Error) -> Self {

snix/nix-compat/src/wire/ser/writer.rs

@@ -203,7 +203,7 @@ where
         }
         let offset = self.buf.len();
         self.buf.put_u64_le(0);
-        if let Err(err) = write!(self.buf, "{}", msg) {
+        if let Err(err) = write!(self.buf, "{msg}") {
             self.buf.truncate(offset);
             return Err(Self::Error::unsupported_data(err));
         }

snix/serde/examples/cfg-demo.rs

@@ -31,5 +31,5 @@ fn main() {
     // Now you can use snix_serde to deserialise the struct:
     let foods: Data = snix_serde::from_str(code).expect("deserialisation should succeed");
 
-    println!("These are the foods:\n{:#?}", foods);
+    println!("These are the foods:\n{foods:#?}");
 }

snix/serde/examples/nixpkgs.rs

@@ -29,6 +29,6 @@ fn main() {
 
     match result {
         Ok(cfg) => println!("Config says: {}:{}", cfg.host, cfg.port),
-        Err(e) => eprintln!("{:?} / {}", e, e),
+        Err(e) => eprintln!("{e:?} / {e}"),
     }
 }

snix/serde/src/error.rs

@@ -41,16 +41,15 @@ impl Display for Error {
         match self {
             Error::Unserializable { value_type } => write!(
                 f,
-                "can not deserialise a Nix '{}' into a Rust type",
+                "can not deserialise a Nix '{value_type}' into a Rust type"
-                value_type
             ),
 
             Error::Unsupported { wanted } => {
-                write!(f, "can not deserialize a '{}' from a Nix value", wanted)
+                write!(f, "can not deserialize a '{wanted}' from a Nix value")
             }
 
             Error::UnexpectedType { expected, got } => {
-                write!(f, "expected type {}, but got Nix type {}", expected, got)
+                write!(f, "expected type {expected}, but got Nix type {got}")
             }
 
             Error::NixErrors { errors } => {
@@ -67,10 +66,10 @@ impl Display for Error {
                 Ok(())
             }
 
-            Error::Deserialization(err) => write!(f, "deserialisation error occured: {}", err),
+            Error::Deserialization(err) => write!(f, "deserialisation error occured: {err}"),
 
             Error::IntegerConversion { got, need } => {
-                write!(f, "i64({}) does not fit in a {}", got, need)
+                write!(f, "i64({got}) does not fit in a {need}")
             }
 
             Error::AmbiguousEnum => write!(f, "could not determine enum variant: ambiguous keys"),

snix/store/src/bin/snix-store.rs

@@ -287,7 +287,7 @@ async fn run_cli(
                     async move {
                         let span = Span::current();
                         span.pb_set_style(&snix_tracing::PB_SPINNER_STYLE);
-                        span.pb_set_message(&format!("Ingesting {:?}", path));
+                        span.pb_set_message(&format!("Ingesting {path:?}"));
                         span.pb_start();
 
                         // Ingest the contents at the given path into castore.
@@ -300,7 +300,7 @@ async fn run_cli(
                         .await
                         .map_err(std::io::Error::custom)?;
 
-                        span.pb_set_message(&format!("NAR Calculation for {:?}", path));
+                        span.pb_set_message(&format!("NAR Calculation for {path:?}"));
 
                         // Ask for the NAR size and sha256
                         let (nar_size, nar_sha256) =

snix/store/src/import.rs

@@ -94,7 +94,7 @@ where
     let root_node =
         ingest_path::<_, _, _, &[u8]>(blob_service, directory_service, path.as_ref(), None)
             .await
-            .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, e))?;
+            .map_err(std::io::Error::other)?;
 
     // Ask for the NAR size and sha256
     let (nar_size, nar_sha256) = nar_calculation_service.calculate_nar(&root_node).await?;
@@ -108,7 +108,7 @@ where
         store_path::build_ca_path(name, &ca, std::iter::empty::<&str>(), false).map_err(|_| {
             std::io::Error::new(
                 std::io::ErrorKind::InvalidData,
-                format!("invalid name: {}", name),
+                format!("invalid name: {name}"),
             )
         })?;
 

snix/store/src/nar/renderer.rs

@@ -39,7 +39,7 @@ where
             self.directory_service.clone(),
         )
         .await
-        .map_err(|e| snix_castore::Error::StorageError(format!("failed rendering nar: {}", e)))
+        .map_err(|e| snix_castore::Error::StorageError(format!("failed rendering nar: {e}")))
     }
 }
 

snix/store/src/nar/seekable.rs

@@ -245,7 +245,7 @@ impl<B: BlobService + 'static> tokio::io::AsyncSeek for Reader<B> {
 
         let this = &mut *self;
         if this.seeking {
-            return Err(io::Error::new(io::ErrorKind::Other, "Already seeking"));
+            return Err(io::Error::other("Already seeking"));
         }
         this.seeking = true;
 

snix/store/src/pathinfoservice/bigtable.rs

@@ -200,7 +200,7 @@ impl PathInfoService for BigtablePathInfoService {
         let mut response = client
             .read_rows(request)
             .await
-            .map_err(|e| Error::StorageError(format!("unable to read rows: {}", e)))?;
+            .map_err(|e| Error::StorageError(format!("unable to read rows: {e}")))?;
 
         if response.len() != 1 {
             if response.len() > 1 {
@@ -241,7 +241,7 @@ impl PathInfoService for BigtablePathInfoService {
 
         // Try to parse the value into a PathInfo message
         let path_info_proto = proto::PathInfo::decode(Bytes::from(cell.value))
-            .map_err(|e| Error::StorageError(format!("unable to decode pathinfo proto: {}", e)))?;
+            .map_err(|e| Error::StorageError(format!("unable to decode pathinfo proto: {e}")))?;
 
         let path_info = PathInfo::try_from(path_info_proto)
             .map_err(|e| Error::StorageError(format!("Invalid path info: {e}")))?;
@@ -294,7 +294,7 @@ impl PathInfoService for BigtablePathInfoService {
                 ],
             })
             .await
-            .map_err(|e| Error::StorageError(format!("unable to mutate rows: {}", e)))?;
+            .map_err(|e| Error::StorageError(format!("unable to mutate rows: {e}")))?;
 
         if resp.predicate_matched {
             trace!("already existed")
@@ -321,12 +321,12 @@ impl PathInfoService for BigtablePathInfoService {
             let mut rows = client
                 .stream_rows(request)
                 .await
-                .map_err(|e| Error::StorageError(format!("unable to read rows: {}", e)))?.enumerate();
+                .map_err(|e| Error::StorageError(format!("unable to read rows: {e}")))?.enumerate();
 
             use futures::stream::StreamExt;
 
             while let Some((i, elem)) = rows.next().await {
-                let (row_key, mut cells) = elem.map_err(|e| Error::StorageError(format!("unable to stream row {}: {}", i, e)))?;
+                let (row_key, mut cells) = elem.map_err(|e| Error::StorageError(format!("unable to stream row {i}: {e}")))?;
                 let span = Span::current();
                 span.record("row.key", bstr::BStr::new(&row_key).to_string());
 
@@ -351,7 +351,7 @@ impl PathInfoService for BigtablePathInfoService {
 
                 // Try to parse the value into a PathInfo message.
                 let path_info_proto = proto::PathInfo::decode(Bytes::from(cell.value))
-                    .map_err(|e| Error::StorageError(format!("unable to decode pathinfo proto: {}", e)))?;
+                    .map_err(|e| Error::StorageError(format!("unable to decode pathinfo proto: {e}")))?;
 
                 let path_info = PathInfo::try_from(path_info_proto).map_err(|e| Error::StorageError(format!("Invalid path info: {e}")))?;
 
@@ -449,7 +449,7 @@ impl TryFrom<url::Url> for BigtableParameters {
             .append_pair("instance_name", &instance_name);
 
         let params: BigtableParameters = serde_qs::from_str(url.query().unwrap_or_default())
-            .map_err(|e| Error::InvalidRequest(format!("failed to parse parameters: {}", e)))?;
+            .map_err(|e| Error::InvalidRequest(format!("failed to parse parameters: {e}")))?;
 
         Ok(params)
     }

snix/store/src/pathinfoservice/from_addr.rs

@@ -36,7 +36,7 @@ pub async fn from_addr(
 ) -> Result<Arc<dyn PathInfoService>, Box<dyn std::error::Error + Send + Sync>> {
     #[allow(unused_mut)]
     let mut url =
-        Url::parse(uri).map_err(|e| Error::StorageError(format!("unable to parse url: {}", e)))?;
+        Url::parse(uri).map_err(|e| Error::StorageError(format!("unable to parse url: {e}")))?;
 
     let path_info_service_config = with_registry(&REG, || {
         <DeserializeWithRegistry<Box<dyn ServiceBuilder<Output = dyn PathInfoService>>>>::try_from(

snix/store/src/pathinfoservice/nix_http.rs

@@ -212,7 +212,7 @@ where
             &narinfo.ca,
         )
         .await
-        .map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;
+        .map_err(io::Error::other)?;
 
         // ensure the ingested narhash and narsize do actually match.
         if narinfo.nar_size != nar_size {

snix/store/src/tests/nar_renderer.rs

@@ -31,7 +31,7 @@ async fn single_file_missing_blob(
         crate::nar::RenderError::NARWriterError(e) => {
             assert_eq!(io::ErrorKind::NotFound, e.kind());
         }
-        _ => panic!("unexpected error: {:?}", e),
+        _ => panic!("unexpected error: {e:?}"),
     }
 }
 
@@ -60,10 +60,10 @@ async fn seekable(
         (Ok(_), Err(_)) => panic!("creating reader should have failed but succeeded"),
         (Ok(_), Ok(Err(_))) => panic!("creating reader should have failed but succeeded"),
         (Err(err), Ok(Ok(_))) => {
-            panic!("creating reader should have succeeded but failed: {}", err)
+            panic!("creating reader should have succeeded but failed: {err}")
         }
         (Err(reader_err), Err(expected_err)) => {
-            assert_eq!(format!("{}", reader_err), format!("{}", expected_err));
+            assert_eq!(format!("{reader_err}"), format!("{}", expected_err));
         }
         (Err(reader_err), Ok(Err(expected_err))) => {
             let crate::nar::RenderError::NARWriterError(e) = reader_err else {

snix/store/src/tests/nar_renderer_seekable.rs

@@ -30,9 +30,9 @@ async fn read_to_end(
 
     match (reader_result, test_output) {
         (Ok(_), Err(_)) => panic!("creating reader should have failed but succeeded"),
-        (Err(err), Ok(_)) => panic!("creating reader should have succeeded but failed: {}", err),
+        (Err(err), Ok(_)) => panic!("creating reader should have succeeded but failed: {err}"),
         (Err(reader_err), Err(expected_err)) => {
-            assert_eq!(format!("{}", reader_err), format!("{}", expected_err));
+            assert_eq!(format!("{reader_err}"), format!("{}", expected_err));
         }
         (Ok(mut reader), Ok(expected_read_result)) => {
             let mut buf: Vec<u8> = vec![];
@@ -41,7 +41,7 @@ async fn read_to_end(
             match (read_result, expected_read_result) {
                 (Ok(_), Err(_)) => panic!("read_to_end should have failed but succeeded"),
                 (Err(err), Ok(_)) => {
-                    panic!("read_to_end should have succeeded but failed: {}", err)
+                    panic!("read_to_end should have succeeded but failed: {err}")
                 }
                 (Err(read_err), Err(expected_read_err)) => {
                     assert_eq!(read_err.kind(), expected_read_err);