fix placeholder not substituted in passAsFile

(cherry picked from commit 12556e570924315eb25ad6057b6c2c5162955e4f)
Signed-off-by: Domen Kožar <domen@dev.si>

src/libstore/build.cc

@@ -2464,7 +2464,7 @@ void DerivationGoal::initTmpDir() {
             } else {
                 string fn = ".attr-" + std::to_string(fileNr++);
                 Path p = tmpDir + "/" + fn;
-                writeFile(p, i.second);
+                writeFile(p, rewriteStrings(i.second, inputRewrites));
                 chownToBuilder(p);
                 env[i.first + "Path"] = tmpDirInSandbox + "/" + fn;
             }