Before: function! TestCallback(buffer, output) return [ \ { \ 'lnum': 1, \ 'bufnr': 1, \ 'vcol': 0, \ 'linter_name': 'testlinter', \ 'nr': -1, \ 'type': 'E', \ 'col': 1, \ 'text': 'Test Error', \ }, \] endfunction call ale#linter#Define('foobar', { \ 'name': 'testlinter', \ 'callback': 'TestCallback', \ 'executable': 'echo', \ 'command': 'echo', \}) let g:ale_buffer_info = {} After: delfunction TestCallback call ale#linter#Reset() let g:ale_buffer_info = {} Given foobar (Some imaginary filetype): foo bar baz Execute(ALE shouldn't blow up when run from a sandbox): AssertEqual 'foobar', &filetype sandbox call ale#Queue(0) sandbox call ale#Queue(1) sandbox call ale#Lint() Execute(ALE shouldn't blow up if file cleanup happens in a sandbox): let g:ale_buffer_info[3] = { \ 'temporary_file_list': ['/tmp/foo'], \ 'temporary_directory_list': ['/tmp/bar'], \} sandbox call ale#engine#RemoveManagedFiles(3) AssertEqual ['/tmp/foo'], g:ale_buffer_info[3].temporary_file_list AssertEqual ['/tmp/bar'], g:ale_buffer_info[3].temporary_directory_list