Conditionally create symlink to agda-mode if present

nixos/tests/agda/base.nix

@@ -24,6 +24,10 @@ in
     };
 
   testScript = ''
+    # agda and agda-mode are in path
+    machine.succeed("agda --version")
+    machine.succeed("agda-mode")
+
     # Minimal script that typechecks
     machine.succeed("touch TestEmpty.agda")
     machine.succeed("agda TestEmpty.agda")

nixos/tests/agda/override-with-backend.nix

@@ -47,8 +47,9 @@ in
     };
 
   testScript = ''
-    # agda executable is not present
+    # agda and agda-mode are not in path
     machine.fail("agda --version")
+    machine.fail("agda-mode")
     # backend is present
     text = machine.succeed("${mainProgram} --help")
     assert "${mainProgram}" in text

pkgs/build-support/agda/default.nix

@@ -71,6 +71,9 @@ let
         makeWrapper ${lib.getExe Agda} $out/bin/${Agda.meta.mainProgram} \
           ${lib.optionalString (ghc != null) ''--add-flags "--with-compiler=${ghc}/bin/ghc"''} \
           --add-flags "--library-file=${libraryFile}"
+        if [ -e ${lib.getExe' Agda "agda-mode"} ]; then
+          ln -s ${lib.getExe' Agda "agda-mode"} $out/bin/agda-mode
+        fi
       '';
 
   withPackages = arg: if isAttrs arg then withPackages' arg else withPackages' { pkgs = arg; };