gnome.eog: Hardcode library path in gir

By default, gobject-introspection refers to libraries using their
file name in the GIR file. Since we do not have FHS to reliably
find libraries by their name, we are patching gobject-introspection
to use absolute paths.

This works fine for libraries installed to "$out/lib" but when a different
path is used, the hard-coded absolute path will be incorrect.
To deal with this case, we also patch Meson to be able
to pass the install_dir to gobject-introspection.
But it currently only passes the data for targets
that have absolute install_dir set.

To have correct libeog path, we therefore need to absolutize the install_dir.

pkgs/desktops/gnome/core/eog/default.nix

@@ -38,6 +38,13 @@ stdenv.mkDerivation rec {
     sha256 = "sha256-+zW/tRZ6QhIfWae5t6wNdbvQUXua/W2Rgx6E01c13fg=";
   };
 
+  patches = [
+    # Fix path to libeog.so in the gir file.
+    # We patch gobject-introspection to hardcode absolute paths but
+    # our Meson patch will only pass the info when install_dir is absolute as well.
+    ./fix-gir-lib-path.patch
+  ];
+
   nativeBuildInputs = [
     meson
     ninja

pkgs/desktops/gnome/core/eog/fix-gir-lib-path.patch

@@ -0,0 +1,13 @@
+diff --git a/src/meson.build b/src/meson.build
+index cc9d3856..f909836d 100644
+--- a/src/meson.build
++++ b/src/meson.build
+@@ -165,7 +165,7 @@ libeog = shared_library(
+   link_args: ldflags,
+   link_depends: symbol_map,
+   install: true,
+-  install_dir: eog_pkglibdir,
++  install_dir: eog_prefix / eog_pkglibdir,
+ )
+ 
+ libeog_dep = declare_dependency(