buildVimPlugin: check that neovim can require the module.

Add:
```
    doInstallCheck = true;
    nvimRequireCheck = "toto";
```
to your vimPluginCall.

pkgs/applications/editors/vim/plugins/build-vim-plugin.nix

@@ -3,6 +3,7 @@
 , vim
 , vimCommandCheckHook
 , vimGenDocHook
+, neovimRequireCheckHook
 }:
 
 rec {
@@ -31,7 +32,7 @@ rec {
       forceShare= [ "man" "info" ];
 
       nativeBuildInputs = attrs.nativeBuildInputs or []
-      ++ [ vimCommandCheckHook ]
+      ++ [ vimCommandCheckHook neovimRequireCheckHook ]
       ++ lib.optional (stdenv.hostPlatform == stdenv.buildPlatform) vimGenDocHook;
       inherit unpackPhase configurePhase buildPhase addonInfo preInstall postInstall;
 

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

@@ -0,0 +1,21 @@
+# Setup hook for checking whether Python imports succeed
+echo "Sourcing neovim-require-check-hook.sh"
+
+neovimRequireCheckHook () {
+    echo "Executing neovimRequireCheckHook"
+
+    if [ -n "$nvimRequireCheck" ]; then
+        echo "Check whether the following module can be imported: $nvimRequireCheck"
+
+		# editorconfig-checker-disable
+        export HOME="$TMPDIR"
+        @nvimBinary@ -es -n -u NONE -i NONE --clean -V1 \
+            --cmd "set rtp+=$out" \
+            --cmd "lua require('$nvimRequireCheck')"
+    fi
+}
+
+echo "Using neovimRequireCheckHook"
+preDistPhases+=" neovimRequireCheckHook"
+
+

pkgs/applications/editors/vim/plugins/overrides.nix

@@ -321,6 +321,9 @@ self: super: {
       sed -Ei lua/plenary/curl.lua \
           -e 's@(command\s*=\s*")curl(")@\1${curl}/bin/curl\2@'
     '';
+
+    doInstallCheck = true;
+    nvimRequireCheck = "plenary";
   });
 
   gruvbox-nvim = super.gruvbox-nvim.overrideAttrs (old: {

pkgs/applications/editors/vim/plugins/vim-utils.nix

@@ -531,8 +531,18 @@ rec {
       };
     } ./vim-command-check-hook.sh) {};
 
+  neovimRequireCheckHook = callPackage ({ neovim-unwrapped }:
+    makeSetupHook {
+      name = "neovim-require-check-hook";
+      deps = [ neovim-unwrapped ];
+      substitutions = {
+        nvimBinary = "${neovim-unwrapped}/bin/nvim";
+        inherit rtpPath;
+      };
+    } ./neovim-require-check-hook.sh) {};
+
   inherit (import ./build-vim-plugin.nix {
-    inherit lib stdenv rtpPath vim vimGenDocHook vimCommandCheckHook;
+    inherit lib stdenv rtpPath vim vimGenDocHook vimCommandCheckHook neovimRequireCheckHook;
   }) buildVimPlugin buildVimPluginFrom2Nix;