E486：找不到模式

在vim 9.0.9中，启动20240205安装的vim-easycomplete，设置情况如下

let g:easycomplete_tabnine_enable = 0
let g:easycomplete_dia_gnostisc_next = ""
let g:easycomplete_dia_gnostisc_prev = ""
let g:easycomplete_nerd_font = 1
let g:easycomplete_tab_trigger = ""
let g:easycomplete_shift_tab_trigger = ""

在编辑.vimrc时，补全会频繁出现如题的错误，输入的字符没有上字，再敲一下会发现两次输入一起上字了，退格也是如此……编辑julia文件时又没有发现这种情况，很长时间没更新了，最近刚更新了插件就遇上了……

在nvim 0.9.1中测试也有这个问题，但是该错误提示会一闪即逝，基本不影响到打字，不像vim会卡在那里……

No source file or test is named. Reproduce the input behavior in Vim 9.0.9 with the listed vim-easycomplete settings, then compare it with Neovim 0.9.1 and Julia editing; done means the E486 error no longer blocks or delays typed characters and backspaces.

Written by the indexing model from the issue text.