myxer: init at 1.3.0

Myxer was previously included in Nixpkgs, but was removed after some build issues.

pkgs/by-name/my/myxer/package.nix

@@ -0,0 +1,44 @@
+{ lib
+, rustPlatform
+, fetchFromGitHub
+, pkg-config
+, wrapGAppsHook
+, libpulseaudio
+, glib
+, pango
+, gtk3
+}:
+
+rustPlatform.buildRustPackage rec {
+  pname = "myxer";
+  version = "1.3.0";
+
+  src = fetchFromGitHub {
+    owner = "Aurailus";
+    repo = "myxer";
+    rev = version;
+    hash = "sha256-c5SHjnhWLp0jMdmDlupMTA0hWphub5DFY1vOI6NW8E0=";
+  };
+
+  cargoHash = "sha256-IH+SLIHO/wu+przH+mgOEnH9m+iAE5s/BJhh0UUHR/0=";
+
+  nativeBuildInputs = [ pkg-config wrapGAppsHook ];
+
+  buildInputs = [ libpulseaudio glib pango gtk3 ];
+
+  postInstall = ''
+    install -Dm644 Myxer.desktop $out/share/applications/Myxer.desktop
+  '';
+
+  # Currently no tests are implemented, so we avoid building the package twice
+  doCheck = false;
+
+  meta = with lib; {
+    description = "A modern Volume Mixer for PulseAudio";
+    homepage = "https://github.com/Aurailus/Myxer";
+    license = licenses.gpl3Only;
+    maintainers = with maintainers; [ erin rster2002 ];
+    mainProgram = "myxer";
+    platforms = platforms.linux;
+  };
+}