Switch back to nixpkgs-unstable by default

lib/shared/home-manager-packages.nix

@@ -32,6 +32,7 @@ with pkgs;
   cachix
   ctop
   delta
+  devenv
   dog
   doppler
   entr
@@ -68,8 +69,6 @@ with pkgs;
   xh
   yarn
 
-  unstable.devenv
-
   # Scripts.
   create-zellij-session
   deliver

lib/shared/home-manager.nix

@@ -11,6 +11,17 @@
   # Nicely reload system units when changing configs.
   systemd.user.startServices = "sd-switch";
 
+  # See https://github.com/nix-community/home-manager/issues/2064#issuecomment-2259307514.
+  # This is a workaround for the following errors that appeared when switching back to unstable:
+  # - 1: Failed to start unit flameshot.service
+  # - 2: org.freedesktop.systemd1.NoSuchUnit: Unit tray.target not found.
+  systemd.user.targets.tray = {
+    Unit = {
+      Description = "Home Manager System Tray";
+      Requires = [ "graphical-session-pre.target" ];
+    };
+  };
+
   home.stateVersion = "22.05";
 
   programs.home-manager.enable = true;