glycin-loaders: init at 0.1.beta.2

https://gitlab.gnome.org/sophie-h/glycin/-/commits/0.1.beta.2

This builds the "loaders" part of the project. This will be needed
for "glycin" the library, and will be needed for new loupe to actually
open any images.

Co-authored-by: Jan Tojnar <jtojnar@gmail.com>

pkgs/by-name/gl/glycin-loaders/fix-glycin-paths.patch

@@ -0,0 +1,13 @@
+diff --git a/vendor/glycin/src/dbus.rs b/vendor/glycin/src/dbus.rs
+index aa5a876..4f37420 100644
+--- a/vendor/glycin/src/dbus.rs
++++ b/vendor/glycin/src/dbus.rs
+@@ -43,7 +43,7 @@ impl<'a> DecoderProcess<'a> {
+ 
+         let (bin, args, final_arg) = match sandbox_mechanism {
+             SandboxMechanism::Bwrap => (
+-                "bwrap".into(),
++                "@bwrap@".into(),
+                 vec![
+                     "--unshare-all",
+                     "--die-with-parent",

pkgs/by-name/gl/glycin-loaders/package.nix

@@ -0,0 +1,70 @@
+{ stdenv
+, lib
+, fetchurl
+, substituteAll
+, bubblewrap
+, cargo
+, git
+, meson
+, ninja
+, pkg-config
+, rustc
+, gtk4
+, cairo
+, libheif
+, libxml2
+, gnome
+}:
+
+stdenv.mkDerivation (finalAttrs: {
+  pname = "glycin-loaders";
+  version = "0.1.beta.2";
+
+  src = fetchurl {
+    url = "mirror://gnome/sources/glycin-loaders/${lib.versions.majorMinor finalAttrs.version}/glycin-loaders-${finalAttrs.version}.tar.xz";
+    hash = "sha256-GwxwHzMDVFWJTfmK/CEoICSLExJyuDv72/g1EOGciBM=";
+  };
+
+  patches = [
+    # Fix paths in glycin library.
+    # Not actually needed for this package since we are only building loaders
+    # and this patch is relevant just to apps that use the loaders
+    # but apply it here to ensure the patch continues to apply.
+    finalAttrs.passthru.glycinPathsPatch
+  ];
+
+  nativeBuildInputs = [
+    cargo
+    git
+    meson
+    ninja
+    pkg-config
+    rustc
+  ];
+
+  buildInputs = [
+    gtk4 # for GdkTexture
+    cairo
+    libheif
+    libxml2 # for librsvg crate
+  ];
+
+  passthru = {
+    updateScript = gnome.updateScript {
+      packageName = "glycin-loaders";
+    };
+
+    glycinPathsPatch = substituteAll {
+      src = ./fix-glycin-paths.patch;
+      bwrap = "${bubblewrap}/bin/bwrap";
+    };
+  };
+
+  meta = with lib; {
+    description = "Glycin loaders for several formats";
+    homepage = "https://gitlab.gnome.org/sophie-h/glycin";
+    maintainers = teams.gnome.members;
+    license = licenses.lgpl21Only;
+    platforms = platforms.linux;
+  };
+})