Cannot map :WhichKey "<CR>"

[hk0i]

Environment (please complete the following information):

• OS: Mac OS 10.15.4
• (Neo)Vim version: 0.4.3
• vim-which-key version: (not sure where to find version?)
• Have you reproduced with a minimal vimrc: no

Describe the bug
:WhichKey "<CR>" works when typing it by hand, but mapping it to a key produces message:

E114: Missing quote ")
E116: Invalid arguments for function which_key#start

To Reproduce
Steps to reproduce the behavior:

1. Make some mappings with as leader (optional)
2. :nnoremap :WhichKey "<CR>"<CR>
3. Error shows

Expected behavior
Whichkey should function as it normally does in command mode

[lifeBalance]

If you use vim-plug, try to update the vim-which-key plugin with :PlugUpdate. I also had issues with the <cr> key, but liuchengxu added support for that key. ;-)

[rene-descartes2021]

I don't know the state of things when lifeBalance had things working.

Reproduced OP's report with:

let mapleader = "\<CR>"
let g:map = {}
let g:map.l = {'name':'+holiday', '1': ['echom ''merry xmas''', 'say greeting']}
call which_key#register('<CR>', 'g:map')
nnoremap <leader> :WhichKey '<CR>'<CR>

:WhichKey '<CR>' works as reported in command mode, but in normal mode doesn't.

I suppose this may have to do with the use of <args> in which_key#start(). Replacing that with <q-args> might help with this specific case, it might do some escape and un-escape magic.

Suggested workaround:

let F=function({->execute(':WhichKey "<CR>"','')})
nnoremap <leader> :call F()<CR>

Could probably make that a one-liner if you wanted.