imlib2: add some key reverse-dependencies to passthru.tests

pkgs/development/libraries/imlib2/default.nix

@@ -9,6 +9,15 @@
 # https://github.com/NixOS/nixpkgs/pull/166452#issuecomment-1090725613
 , svgSupport ? !stdenv.isDarwin
 , heifSupport ? !stdenv.isDarwin
+
+# for passthru.tests
+, libcaca
+, diffoscopeMinimal
+, feh
+, icewm
+, openbox
+, fluxbox
+, enlightenment
 }:
 
 let
@@ -43,6 +52,17 @@ stdenv.mkDerivation rec {
 
   outputs = [ "bin" "out" "dev" ];
 
+  passthru.tests = {
+    inherit
+      libcaca
+      diffoscopeMinimal
+      feh
+      icewm
+      openbox
+      fluxbox
+      enlightenment;
+  };
+
   meta = with lib; {
     description = "Image manipulation library";