patch 8.1.1805: au_did_filetype is declared twice commit https://github.com/vim/vim/commit/6cd57d44669c02af9195f5601b882edd435b47e8 Author: Bram Moolenaar <Bram@vim.org> Date: Sat Aug 3 23:08:14 2019 +0200 patch 8.1.1805: au_did_filetype is declared twice Problem: Au_did_filetype is declared twice. Solution: Remove it from autocmd.c. (closes https://github.com/vim/vim/issues/4767)

" Vim support file to switch off loading plugins for file types
"
" Maintainer:	Bram Moolenaar <Bram@vim.org>
" Last Change:	2011 Oct 20

if exists("did_load_ftplugin")
  unlet did_load_ftplugin
endif

" Remove all autocommands in the filetypeplugin group, if any exist.
if exists("#filetypeplugin")
  silent! au! filetypeplugin *
endif