beets: refactor external plugins into top-level package set

Instead of managing external plugins in the beets derivation, we
introduce a new top-level package set beetsExternalPlugins which the
beets derivation receives as an input. This change doesn't affect how
the beets derivation is built or overridden, so the change won't be
noticed by users, but it makes hydra evaluate and build external plugins
which should benefit users of those plugins and prevent future
regressions as we have experienced (currently on master
beets-alternatives fails to evaluate, but this wasn't picked up by
ofborg nor hydra).

pkgs/tools/audio/beets/default.nix

@@ -3,8 +3,8 @@
 , runtimeShell
 , unstableGitUpdater
 
-# Attributes needed for tests of the external plugins
-, callPackage, beets
+# external plugins package set
+, beetsExternalPlugins
 
 , enableAbsubmit         ? lib.elem stdenv.hostPlatform.system essentia-extractor.meta.platforms, essentia-extractor ? null
 , enableAcousticbrainz   ? true
@@ -116,15 +116,6 @@ let
     doInstallCheck = false;
   });
 
-  pluginArgs = externalTestArgs // { inherit pythonPackages; };
-
-  plugins = {
-    alternatives = callPackage ./plugins/alternatives.nix pluginArgs;
-    check = callPackage ./plugins/check.nix pluginArgs;
-    copyartifacts = callPackage ./plugins/copyartifacts.nix pluginArgs;
-    extrafiles = callPackage ./plugins/extrafiles.nix pluginArgs;
-  };
-
 in pythonPackages.buildPythonApplication rec {
   pname = "beets";
   # While there is a stable version, 1.4.9, it is more than 1000 commits behind
@@ -169,7 +160,7 @@ in pythonPackages.buildPythonApplication rec {
               || enableSubsonicupdate
               || enableAcousticbrainz)
                                     pythonPackages.requests
-    ++ optional enableCheck         plugins.check
+    ++ optional enableCheck         beetsExternalPlugins.check
     ++ optional enableConvert       ffmpeg
     ++ optional enableDiscogs       pythonPackages.discogs_client
     ++ optional enableGmusic        pythonPackages.gmusicapi
@@ -179,9 +170,9 @@ in pythonPackages.buildPythonApplication rec {
     ++ optional enableSonosUpdate   pythonPackages.soco
     ++ optional enableThumbnails    pythonPackages.pyxdg
     ++ optional enableWeb           pythonPackages.flask
-    ++ optional enableAlternatives  plugins.alternatives
-    ++ optional enableCopyArtifacts plugins.copyartifacts
-    ++ optional enableExtraFiles    plugins.extrafiles
+    ++ optional enableAlternatives  beetsExternalPlugins.alternatives
+    ++ optional enableCopyArtifacts beetsExternalPlugins.copyartifacts
+    ++ optional enableExtraFiles    beetsExternalPlugins.extrafiles
   ;
 
   buildInputs = [
@@ -289,7 +280,8 @@ in pythonPackages.buildPythonApplication rec {
   makeWrapperArgs = [ "--set GI_TYPELIB_PATH \"$GI_TYPELIB_PATH\"" "--set GST_PLUGIN_SYSTEM_PATH_1_0 \"$GST_PLUGIN_SYSTEM_PATH_1_0\"" ];
 
   passthru = {
-    externalPlugins = plugins;
+    # FIXME: remove in favor of pkgs.beetsExternalPlugins
+    externalPlugins = beetsExternalPlugins;
     updateScript = unstableGitUpdater { url = "https://github.com/beetbox/beets"; };
   };
 

pkgs/top-level/all-packages.nix

@@ -3009,6 +3009,26 @@ in
     pythonPackages = python3Packages;
   };
 
+  beetsExternalPlugins =
+    let
+      pluginArgs = {
+        # This is a stripped down beets for testing of the external plugins.
+        beets = (beets.override {
+          enableAlternatives = false;
+          enableCopyArtifacts = false;
+          enableExtraFiles = false;
+        }).overrideAttrs (lib.const {
+          doInstallCheck = false;
+        });
+        pythonPackages = python3Packages;
+      };
+    in lib.recurseIntoAttrs {
+      alternatives = callPackage ../tools/audio/beets/plugins/alternatives.nix pluginArgs;
+      check = callPackage ../tools/audio/beets/plugins/check.nix pluginArgs;
+      copyartifacts = callPackage ../tools/audio/beets/plugins/copyartifacts.nix pluginArgs;
+      extrafiles = callPackage ../tools/audio/beets/plugins/extrafiles.nix pluginArgs;
+    };
+
   bento4 = callPackage ../tools/video/bento4 { };
 
   bepasty = callPackage ../tools/misc/bepasty { };