Bug: quickfix extension crashes on %

[harriott]

Self Checks

• I'm using the latest lualine.
• I didn't find the issue in existing issues or PRs.

How to reproduce the problem

with quickfix extension enabled, vimgrep for '%' then try to open quickfix

Expected behaviour

Nvim's quickfix window opens normally.

Actual behaviour

See many instances of this error report:

Error executing vim.schedule lua callback: ...vim/plugged/lualine.nvim/lua/lualine/utils/nvim_opts.lua:77: E539: Illegal character </>
stack traceback:
[C]: in function 'nvim_win_set_option'
...vim/plugged/lualine.nvim/lua/lualine/utils/nvim_opts.lua:77: in function 'setter_fn'
...vim/plugged/lualine.nvim/lua/lualine/utils/nvim_opts.lua:50: in function 'set_opt'
...vim/plugged/lualine.nvim/lua/lualine/utils/nvim_opts.lua:74: in function 'set'
...e/.local/share/nvim/plugged/lualine.nvim/lua/lualine.lua:432: in function 'refresh'
...e/.local/share/nvim/plugged/lualine.nvim/lua/lualine.lua:353: in function <...e/.local/share/nvim/plugged/lualine.nvim/lua/lualine.lua:352>
Press ENTER or type command to continue

- requires many Enters...

Minimal config to reproduce the issue

call plug#begin("/home/jo/nvim_lualine/.local/share/nvim/plugged")
Plug 'nvim-lualine/lualine.nvim'
call plug#end()
PlugUpdate

lua << END
require'lualine'.setup {
  extensions = {'quickfix',},
}
END

" quickfix extension fails on vimgrep including '%'
" -------------------------------------------------
edit ~/percent
normal xi%
write
vimgrep /%/ %
cwindow
" now hit Enter to see many instances of the error report

Additional information

Comment on functionality of nvim_isolated_conf.sh:
Could be helpful to include PlugUpdate up there (as I have) with advice to comment it out once done.
I only understood that your script wasn't faulty after making my own vim-plug minimal install.