several nixgl things

home-manager/modules/machine.nix

@@ -55,6 +55,15 @@ with lib; {
         description = "Whether to enable noise suppression or not";
       };
     };
+    nixGLPrefix = lib.mkOption {
+      type = lib.types.str;
+      default = "";
+      description = ''
+        Will be prepended to commands which require working OpenGL.
+
+        This needs to be set to the right nixGL package on non-NixOS systems.
+      '';
+    };
   };
 
   config = {

home-manager/utils/nixGLWrap.nix

@@ -1,17 +1,37 @@
-{ pkgs, lib, ... }:
+# Call once on import to load global context
+{
+  pkgs,
+  config,
+}:
+# Wrap a single package
+pkg:
+if config.nixGLPrefix == ""
+then pkg
+else
+  # Wrap the package's binaries with nixGL, while preserving the rest of
+  # the outputs and derivation attributes.
+  (pkg.overrideAttrs (old: {
+    name = "nixGL-${pkg.name}";
+    buildCommand = ''
+      set -eo pipefail
 
-let nixgl = import <nixgl> { };
-in pkg:
-pkgs.runCommand "${pkg.name}-nixgl-wrapper" { } ''
-  mkdir $out
-  ln -s ${pkg}/* $out
-  rm $out/bin
-  mkdir $out/bin
-  for bin in ${pkg}/bin/*; do
-  wrapped_bin=$out/bin/$(basename $bin)
-  echo -e "#!/bin/bash\nexec ${
-    lib.getExe nixgl.auto.nixGLDefault
-  } $bin \$@" > $wrapped_bin
-  chmod +x $wrapped_bin
-  done
-''
+      ${
+        # Heavily inspired by https://stackoverflow.com/a/68523368/6259505
+        pkgs.lib.concatStringsSep "\n" (map (outputName: ''
+          echo "Copying output ${outputName}"
+          set -x
+          cp -rs --no-preserve=mode "${pkg.${outputName}}" "''$${outputName}"
+          set +x
+        '') (old.outputs or ["out"]))
+      }
+
+      rm -rf $out/bin/*
+      shopt -s nullglob # Prevent loop from running if no files
+      for file in ${pkg.out}/bin/*; do
+        echo "#!${pkgs.bash}/bin/bash" > "$out/bin/$(basename $file)"
+        echo "exec -a \"\$0\" ${config.nixGLPrefix} $file \"\$@\"" >> "$out/bin/$(basename $file)"
+        chmod +x "$out/bin/$(basename $file)"
+      done
+      shopt -u nullglob # Revert nullglob back to its normal default state
+    '';
+  }))