celeste: install desktop file and icons

pkgs/applications/networking/sync/celeste/default.nix

@@ -4,6 +4,7 @@
 , rustPlatform
 , fetchFromGitHub
 , substituteAll
+, just
 , pkg-config
 , wrapGAppsHook4
 , cairo
@@ -48,6 +49,11 @@ rustPlatform.buildRustPackage rec {
     substituteInPlace .cargo-checksum.json \
       --replace $oldHash $(sha256sum build.rs | cut -d " " -f 1)
     popd
+
+    substituteInPlace justfile \
+      --replace "{{ env_var('DESTDIR') }}/usr" "${placeholder "out"}"
+    # buildRustPackage takes care of installing the binary
+    sed -i "#/bin/celeste#d" justfile
   '';
 
   # Cargo.lock is outdated
@@ -66,6 +72,7 @@ rustPlatform.buildRustPackage rec {
   RUSTC_BOOTSTRAP = 1;
 
   nativeBuildInputs = [
+    just
     pkg-config
     rustPlatform.bindgenHook
     wrapGAppsHook4
@@ -90,6 +97,10 @@ rustPlatform.buildRustPackage rec {
     )
   '';
 
+  postInstall = ''
+    just install
+  '';
+
   meta = {
     changelog = "https://github.com/hwittenborn/celeste/blob/${src.rev}/CHANGELOG.md";
     description = "GUI file synchronization client that can sync with any cloud provider";