错误符号未在vim-syntastic中显示

Question

我尝试将自定义错误符号添加到我的.vimrc文件中的syntastic中，如下所示：

" Error symbols
let g:syntastic_error_symbol = "✗"
let g:syntastic_warning_symbol ="∙∙"

但我想我已经成功地打破了一些东西。现在，即使是默认的符号也不能正确加载，但是我在左边空白处得到的是S>而不是>>。

所以我不仅不能得到我的自定义符号，也不能得到默认的符号。发生了什么？

完整的语法设置为：

" ============== syntastic settings ===============
set statusline+=%#warningmsg#
set statusline+=%{SyntasticStatuslineFlag()}
set statusline+=%*

let g:syntastic_always_populate_loc_list = 1
let g:syntastic_auto_loc_list = 1
let g:syntastic_check_on_open = 1
let g:syntastic_check_on_wq = 0

" Specific checkers for tex
let g:syntastic_tex_checkers = ['chktex', 'proselint']

" Others
let g:syntastic_aggregate_errors = 1
let g:syntastic_enable_signs = 1

" Error symbols
" let g:syntastic_error_symbol = "✗"
" let g:syntastic_warning_symbol ="∙∙"