gitit: init at 0.13.0.0

This was broken in `haskellPackages` for a long time, but it’s back!

Time to give it a place in the toplevel and a prope) treatment:

* Semi-static binary
* Remove all references to `Paths_` modules of dependencies
* gitit tries very hard to have a runtime dependency on GHC, disable
  that by default.

Also added myself as a maintainer, let’s try to keep this working from
now on.

Fixes https://github.com/NixOS/nixpkgs/issues/32377

1 files changed, 61 insertions, 0 deletions

diff --git a/pkgs/applications/misc/gitit/default.nix b/pkgs/applications/misc/gitit/default.nix
new file mode 100644
index 0000000000000..a4ffd3bf88d3b
--- /dev/null
+++ b/pkgs/applications/misc/gitit/default.nix
@@ -0,0 +1,61 @@
+{ lib, haskellPackages, haskell, removeReferencesTo
+# “Plugins” are a fancy way of saying gitit will invoke
+# GHC at *runtime*, which in turn makes it pull GHC
+# into its runtime closure. Only enable if you really need
+# that feature. But if you do you’ll want to use gitit
+# as a library anyway.
+, pluginSupport ? false
+}:
+
+# this is similar to what we do with the pandoc executable
+
+let
+  plain = haskellPackages.gitit;
+  plugins =
+    if pluginSupport
+    then plain
+    else haskell.lib.disableCabalFlag plain "plugins";
+  static = haskell.lib.justStaticExecutables plugins;
+
+in
+  (haskell.lib.overrideCabal static (drv: {
+    buildTools = (drv.buildTools or []) ++ [ removeReferencesTo ];
+  })).overrideAttrs (drv: {
+
+    # These libraries are still referenced, because they generate
+    # a `Paths_*` module for figuring out their version.
+    # The `Paths_*` module is generated by Cabal, and contains the
+    # version, but also paths to e.g. the data directories, which
+    # lead to a transitive runtime dependency on the whole GHC distribution.
+    # This should ideally be fixed in haskellPackages (or even Cabal),
+    # but a minimal gitit is important enough to patch it manually.
+    disallowedReferences = [
+      haskellPackages.pandoc-types
+      haskellPackages.HTTP
+      haskellPackages.pandoc
+      haskellPackages.happstack-server
+      haskellPackages.filestore
+    ];
+    postInstall = ''
+      remove-references-to \
+        -t ${haskellPackages.pandoc-types} \
+        $out/bin/gitit
+      remove-references-to \
+        -t ${haskellPackages.HTTP} \
+        $out/bin/gitit
+      remove-references-to \
+        -t ${haskellPackages.pandoc} \
+        $out/bin/gitit
+      remove-references-to \
+        -t ${haskellPackages.happstack-server} \
+        $out/bin/gitit
+      remove-references-to \
+        -t ${haskellPackages.filestore} \
+        $out/bin/gitit
+    '';
+
+    meta = drv.meta // {
+      maintainers = drv.meta.maintainers or []
+        ++ [ lib.maintainers.Profpatsch ];
+    };
+  })