CtrlP file indexing breaks in WSL and Neovim, but not gvim.

[tankorsmash]

Hey there!

In Neovim 0.9.1, when I run Neovim Qt from Windows 10 and edit a file in located in WSL (but still running vim in Windows), open CtrlP and hit F5 to rebuild the cache, the cache looks something like this:

Contents of C:\Users\user\.cache\ctrlp\\%%wsl$%UbuntuMoved%home%user%code_wsl%weekend.txt:

UNC paths are not supported.  Defaulting to Windows directory.
'\\wsl.localhost\UbuntuMoved\home\user\code_wsl\weekend'
CMD.EXE was started with the above path as the current directory.
\\wsl.localhost\UbuntuMoved\home\user\code_wsl\weekend\LICENSE
\\wsl.localhost\UbuntuMoved\home\user\code_wsl\weekend\Setup.hs

But when I do the same from gVim v9.0.1425, it looks like the following (as expected)

Contents of C:\Users\user\.cache\ctrlp\\%%wsl$%UbuntuMoved%home%user%code_wsl%weekend.txt:

LICENSE
Setup.hs
README.md

The config for neovim is about 5 lines and sources the original vimrc, so there isn't any configuration difference between the two on my end from what I can tell. I've disabled any ctrlp_user_commandd and custom matchers, which didn't appear to change anything either.

It looks like some interaction with Neovim and Ctrlp breaks when working on Windows through the WSL layer, but the same issue doesn't happen with classic Vim. If this is an issue better suited to the nvim repo, please let me know.