neovim-require-check-hook: remove $out from rtp (#529637)

pkgs/applications/editors/neovim/tests/default.nix

@@ -558,4 +558,25 @@ pkgs.lib.recurseIntoAttrs rec {
       EOF
     '';
   };
+
+  nvim_require_check_rtp_no_duplicate = vimUtils.buildVimPlugin {
+    pname = "neovim-require-check-rtp-no-duplicate-test";
+    version = "0";
+    src = runCommandLocal "neovim-require-check-rtp-no-duplicate-src" { } ''
+      mkdir -p "$out/lua/require-check-rtp-dedup"
+      cat > "$out/lua/require-check-rtp-dedup/init.lua" <<'EOF'
+      local target = "lua/require-check-rtp-dedup/init.lua"
+      local matches = vim.api.nvim_get_runtime_file(target, true)
+      if #matches ~= 1 then
+        error(
+          ("expected plugin on runtimepath exactly once, found %d:\n%s"):format(
+            #matches,
+            table.concat(matches, "\n")
+          )
+        )
+      end
+      return {}
+      EOF
+    '';
+  };
 }

pkgs/applications/editors/vim/plugins/hooks/neovim-require-check-hook.sh

@@ -98,9 +98,9 @@ run_require_checks() {
         if [ "$skip" = false ]; then
             echo "Attempting to require module: $name"
             if @nvimBinary@ -es --headless -n -u NONE -i NONE --clean -V1 \
-                --cmd "set rtp+=$out,${deps// /,}" \
-                --cmd "set rtp+=$out,${nativeCheckInputs// /,}" \
-                --cmd "set rtp+=$out,${checkInputs// /,}" \
+                --cmd "set rtp+=${deps// /,}" \
+                --cmd "set rtp+=${nativeCheckInputs// /,}" \
+                --cmd "set rtp+=${checkInputs// /,}" \
                 "${luaPathArgs[@]}" \
                 --cmd "set packpath^=$packPathDir" \
                 --cmd "packadd testPlugin" \