refactor(fun/gemma): Use buildLisp.nix to build Gemma

This removes the ASDF system definition for Gemma and switches the
code over to buildLisp.

The program builds (including some terrifying hacks to get the
frontend to work), but there are some bizarre runtime issues that I
need to debug.

fun/gemma/default.nix

@@ -1,61 +1,50 @@
 { pkgs, ... }:
 
 let
-  inherit (pkgs) elmPackages lispPackages;
-  inherit (pkgs.third_party) stdenv sbcl makeWrapper openssl;
+  inherit (pkgs) elmPackages;
+  inherit (pkgs.third_party) cacert iana-etc libredirect stdenv runCommandNoCC;
 
   frontend = stdenv.mkDerivation {
-    name = "gemma-frontend";
+    name = "gemma-frontend.html";
     src = ./frontend;
-    buildInputs = [ elmPackages.elm ];
+    buildInputs = [ cacert iana-etc elmPackages.elm ];
+
+    # The individual Elm packages this requires are not packaged and I
+    # can't be bothered to do that now, so lets open the escape hatch:
+    outputHashAlgo = "sha256";
+    outputHash = "000xhds5bsig3kbi7dhgbv9h7myacf34bqvw7avvz7m5mwnqlqg7";
 
     phases = [ "unpackPhase" "buildPhase" ];
     buildPhase = ''
+      export NIX_REDIRECTS=/etc/protocols=${iana-etc}/etc/protocols \
+        LD_PRELOAD=${libredirect}/lib/libredirect.so
+
+      export SYSTEM_CERTIFICATE_PATH=${cacert}/etc/ssl/certs
+
       mkdir .home && export HOME="$PWD/.home"
-      mkdir -p $out
-      elm-make --yes Main.elm --output $out/index.html
+      elm-make --yes Main.elm --output $out
     '';
   };
-in stdenv.mkDerivation rec {
-  name = "gemma";
-  src = ./.;
 
-  nativeBuildInputs = with lispPackages; [
-    sbcl
-    hunchentoot
+  injectFrontend = pkgs.writeText "gemma-frontend.lisp" ''
+    (in-package :gemma)
+    (setq *static-file-location* "${runCommandNoCC "frontend" {} ''
+      mkdir -p $out
+      cp ${frontend} $out/index.html
+    ''}}")
+  '';
+in pkgs.nix.buildLisp.program {
+  name = "gemma";
+
+  deps = with pkgs.third_party.lisp; [
     cl-json
-    cffi
     cl-prevalence
+    hunchentoot
     local-time
-    makeWrapper
   ];
 
-  buildPhase = ''
-    mkdir -p $out/share/gemma $out/bin
-
-    # Build Lisp using the Nix-provided wrapper which sets the load
-    # paths correctly.
-    cd $src
-    env GEMMA_BIN_TARGET=$out/bin/gemma common-lisp.sh --load build.lisp
-
-    # Wrap gemma to find OpenSSL at runtime:
-    wrapProgram $out/bin/gemma --prefix LD_LIBRARY_PATH : "${openssl.out}/lib"
-
-    # and finally copy the frontend to the appropriate spot
-    cp ${frontend}/index.html $out/share/gemma/index.html
-  '';
-
-  installPhase = "true";
-
-  # Stripping an SBCL executable removes the application, which is unfortunate.
-  dontStrip = true;
-
-  meta = with stdenv.lib; {
-    description = "Tool for tracking recurring tasks";
-    homepage    = "https://github.com/tazjin/gemma";
-    license     = licenses.gpl3;
-
-    # Lisp builds are broken for some reason (2019-09-22)
-    broken = true;
-  };
+  srcs = [
+    ./src/gemma.lisp
+    injectFrontend
+  ];
 }