flake: add `overlay` output

1 files changed, 128 insertions, 124 deletions

diff --git a/flake.nix b/flake.nix
index 9ef68722..38477df3 100644
--- a/flake.nix
+++ b/flake.nix
@@ -81,132 +81,10 @@
       packages = forAllSystems (
         system:
         let
-          inherit (self.packages.${system}) niri;
+          inherit (self.overlays.default nixpkgsFor.${system} null) niri;
         in
         {
-          niri = nixpkgsFor.${system}.callPackage (
-            {
-              cairo,
-              clang,
-              dbus,
-              libGL,
-              libclang,
-              libdisplay-info,
-              libinput,
-              libseat,
-              libxkbcommon,
-              mesa,
-              pango,
-              pipewire,
-              pkg-config,
-              rustPlatform,
-              systemd,
-              wayland,
-              withDbus ? true,
-              withSystemd ? true,
-              withScreencastSupport ? true,
-              withDinit ? false,
-            }:
-
-            rustPlatform.buildRustPackage {
-              pname = "niri";
-              version = self.shortRev or self.dirtyShortRev or "unknown";
-
-              src = nix-filter.lib.filter {
-                root = self;
-                include = [
-                  "niri-config"
-                  "niri-ipc"
-                  "niri-visual-tests"
-                  "resources"
-                  "src"
-                  ./Cargo.lock
-                  ./Cargo.toml
-                ];
-              };
-
-              postPatch = ''
-                patchShebangs resources/niri-session
-                substituteInPlace resources/niri.service \
-                  --replace-fail '/usr/bin' "$out/bin"
-              '';
-
-              cargoLock = {
-                # NOTE: This is only used for Git dependencies
-                allowBuiltinFetchGit = true;
-                lockFile = ./Cargo.lock;
-              };
-
-              strictDeps = true;
-
-              nativeBuildInputs = [
-                clang
-                pkg-config
-              ];
-
-              buildInputs =
-                [
-                  cairo
-                  dbus
-                  libGL
-                  libdisplay-info
-                  libinput
-                  libseat
-                  libxkbcommon
-                  mesa # libgbm
-                  pango
-                  wayland
-                ]
-                ++ lib.optional (withDbus || withScreencastSupport || withSystemd) dbus
-                ++ lib.optional withScreencastSupport pipewire
-                # Also includes libudev
-                ++ lib.optional withSystemd systemd;
-
-              buildFeatures =
-                lib.optional withDbus "dbus"
-                ++ lib.optional withDinit "dinit"
-                ++ lib.optional withScreencastSupport "xdp-gnome-screencast"
-                ++ lib.optional withSystemd "systemd";
-              buildNoDefaultFeatures = true;
-
-              postInstall =
-                ''
-                  install -Dm644 resources/niri.desktop -t $out/share/wayland-sessions
-                  install -Dm644 resources/niri-portals.conf -t $out/share/xdg-desktop-portal
-                ''
-                + lib.optionalString withSystemd ''
-                  install -Dm755 resources/niri-session $out/bin/niri-session
-                  install -Dm644 resources/niri{.service,-shutdown.target} -t $out/share/systemd/user
-                '';
-
-              env = {
-                LIBCLANG_PATH = lib.getLib libclang + "/lib";
-
-                # Force linking with libEGL and libwayland-client
-                # so they can be discovered by `dlopen()`
-                CARGO_BUILD_RUSTFLAGS = toString (
-                  map (arg: "-C link-arg=" + arg) [
-                    "-Wl,--push-state,--no-as-needed"
-                    "-lEGL"
-                    "-lwayland-client"
-                    "-Wl,--pop-state"
-                  ]
-                );
-              };
-
-              passthru = {
-                providedSessions = [ "niri" ];
-              };
-
-              meta = {
-                description = "Scrollable-tiling Wayland compositor";
-                homepage = "https://github.com/YaLTeR/niri";
-                license = lib.licenses.gpl3Only;
-                mainProgram = "niri";
-                platforms = lib.platforms.linux;
-              };
-            }
-          ) { };
+          inherit niri;
 
           # NOTE: This is for development purposes only
           #
@@ -227,5 +105,131 @@
           default = niri;
         }
       );
+
+      overlays.default = final: _: {
+        niri = final.callPackage (
+          {
+            cairo,
+            clang,
+            dbus,
+            libGL,
+            libclang,
+            libdisplay-info,
+            libinput,
+            libseat,
+            libxkbcommon,
+            mesa,
+            pango,
+            pipewire,
+            pkg-config,
+            rustPlatform,
+            systemd,
+            wayland,
+            withDbus ? true,
+            withSystemd ? true,
+            withScreencastSupport ? true,
+            withDinit ? false,
+          }:
+
+          rustPlatform.buildRustPackage {
+            pname = "niri";
+            version = self.shortRev or self.dirtyShortRev or "unknown";
+
+            src = nix-filter.lib.filter {
+              root = self;
+              include = [
+                "niri-config"
+                "niri-ipc"
+                "niri-visual-tests"
+                "resources"
+                "src"
+                ./Cargo.lock
+                ./Cargo.toml
+              ];
+            };
+
+            postPatch = ''
+              patchShebangs resources/niri-session
+              substituteInPlace resources/niri.service \
+                --replace-fail '/usr/bin' "$out/bin"
+            '';
+
+            cargoLock = {
+              # NOTE: This is only used for Git dependencies
+              allowBuiltinFetchGit = true;
+              lockFile = ./Cargo.lock;
+            };
+
+            strictDeps = true;
+
+            nativeBuildInputs = [
+              clang
+              pkg-config
+            ];
+
+            buildInputs =
+              [
+                cairo
+                dbus
+                libGL
+                libdisplay-info
+                libinput
+                libseat
+                libxkbcommon
+                mesa # libgbm
+                pango
+                wayland
+              ]
+              ++ lib.optional (withDbus || withScreencastSupport || withSystemd) dbus
+              ++ lib.optional withScreencastSupport pipewire
+              # Also includes libudev
+              ++ lib.optional withSystemd systemd;
+
+            buildFeatures =
+              lib.optional withDbus "dbus"
+              ++ lib.optional withDinit "dinit"
+              ++ lib.optional withScreencastSupport "xdp-gnome-screencast"
+              ++ lib.optional withSystemd "systemd";
+            buildNoDefaultFeatures = true;
+
+            postInstall =
+              ''
+                install -Dm644 resources/niri.desktop -t $out/share/wayland-sessions
+                install -Dm644 resources/niri-portals.conf -t $out/share/xdg-desktop-portal
+              ''
+              + lib.optionalString withSystemd ''
+                install -Dm755 resources/niri-session $out/bin/niri-session
+                install -Dm644 resources/niri{.service,-shutdown.target} -t $out/share/systemd/user
+              '';
+
+            env = {
+              LIBCLANG_PATH = lib.getLib libclang + "/lib";
+
+              # Force linking with libEGL and libwayland-client
+              # so they can be discovered by `dlopen()`
+              CARGO_BUILD_RUSTFLAGS = toString (
+                map (arg: "-C link-arg=" + arg) [
+                  "-Wl,--push-state,--no-as-needed"
+                  "-lEGL"
+                  "-lwayland-client"
+                  "-Wl,--pop-state"
+                ]
+              );
+            };
+
+            passthru = {
+              providedSessions = [ "niri" ];
+            };
+
+            meta = {
+              description = "Scrollable-tiling Wayland compositor";
+              homepage = "https://github.com/YaLTeR/niri";
+              license = lib.licenses.gpl3Only;
+              mainProgram = "niri";
+              platforms = lib.platforms.linux;
+            };
+          }
+        ) { };
+      };
     };
 }