Not compatible with Oni

[brglng]

Problems summary

Dein is not compatible with Oni because of the caching of runtimepath. dein#load_state() overwrites the entire runtimepath, which also contains the runtime paths added by Oni, which are essential for Oni to behave correctly. If I run nvim once before running oni, then the runtimepath will be overwritten to the runtimepath when I previously run nvim, and that causes problems in Oni.

Expected

There should be some mechanisms to deal with such problems, as many GUIs may add their own runtimepaths. But I cannot imagine a good way to solve this at the moment.

Environment Information (Required!)

• dein.vim version(SHA1): 5bbff63
• OS: Ubuntu 17.10
• Vim/neovim version: Neovim v0.2.2

Provide a minimal .vimrc with less than 50 lines (Required!)

set runtimepath+=$HOME/.local/share/dein/repos/github.com/Shougo/dein.vim

let g:dein#install_process_timeout = 3600 * 2

if dein#load_state($HOME . '/.local/share/dein')
  call dein#begin($HOME . '/.local/share/dein')

  call dein#add($HOME . '/.local/share/dein/repos/github.com/Shougo/dein.vim')

  " Required:
  call dein#end()
  call dein#save_state()
endif

The reproduce ways from Vim starting (Required!)

There must be "oni.loadInitVim": true in Oni's config (~/.oni/config.js).

Method 1:

1. Install Dein and plugins in nvim.
2. Open Oni
3. Check if Oni behaves correctly (With some specific settings, Oni can crash when using :q to exit, but I cannot figure out what setting caused that. But if I call dein#clear_state() and restart Oni, it works with no problem.)

Method 2:

1. Install Dein and plugins in nvim.
2. Manually clears Dein's state files.
3. Start Oni and it should work correctly.
4. Exit Oni and start nvim, you should see nvim continuously reports no notification handler registered for "oni_plugin_notify" error. That is because Dein has loaded the runtimepath cache when using Oni before, which does not work in nvim.

Screen shot (if possible)

Upload the log messages by :redir and :message (if errored)

[Shougo]

Hm. It is not dein problem.
dein uses fnamemodify(v:progname, ':r') as the state name.
I think it is same with oni and normal nvim.
So it will be overwritten.

[Shougo]

If oni can tell dein the GUI client name.
I can add the support for it.

[Shougo]

I think you should not share the dein cache directory between normal neovim and Oni.

[brglng]

Hmm... It looks like in Oni v:progname is nvim, which caused problem.

[Shougo]

If plugin can check neovim --headless mode, it can be fixed.

[Shougo]

Oni uses --embed to launch nvim.

https://github.com/onivim/oni/blob/3d53ac2a83b2855b74a8ba367c78b47fe2995788/browser/src/neovim/NeovimProcessSpawner.ts#L118

[Shougo]

dein should check runtimepath in cache loading.

[brglng]

Thank you very much! The fix works great!