WIP: Improve error messaging for invalid recipe files

bin/elinter

@@ -62,7 +62,7 @@ else
 fi
 
 usage() {
-  # Follow the style in docopt https://docopt.org/
+  # Follow the style in docopt http://docopt.org/
   cat <<HELP
 Usage: elinter [options] <recipe>...
 
@@ -273,6 +273,7 @@ copy_package_sources() {
   initialdir="$(pwd)"
   # Operate on each package recipe
   for f in ${recipes[*]}; do
+    echo "Linking package source files for recipe ${f} ..."
     # Use the base name of the recipe file as the package name
     package=$(basename "$f")
     # Convert to an absolute path

nix/copySource.nix

@@ -29,10 +29,14 @@ let
         filter (file: match "(.*/)?flycheck_.+\.el" file == null)
           (expandPackageFiles srcRoot recipeAttrs.files);
       sourceFiles = filter isElisp packageFiles;
+      mainFiles = (filter isMainFile sourceFiles);
       mainFile =
         if length sourceFiles == 1
         then head sourceFiles
-        else head (filter isMainFile sourceFiles);
+        else
+          if mainFiles == [ ]
+          then abort "Main elisp file not found for recipe ${recipeFile}."
+          else head mainFiles;
     };
 in
 with package;