Before: runtime ale_linters/nasm/nasm.vim After: call ale#linter#Reset() Execute(The nasm handler should parse GCC style output from nasm correctly): AssertEqual \ [ \ { \ 'lnum': 2, \ 'text': "label alone on a line without a colon might be in error", \ 'type': 'W', \ }, \ { \ 'lnum': 4, \ 'text': "invalid combination of opcode and operands", \ 'type': 'E', \ }, \ { \ 'lnum': 7, \ 'text': "unable to open include file `bar.asm'", \ 'type': 'E', \ }, \ ], \ ale_linters#nasm#nasm#Handle(357, [ \ "tmp.asm:2: warning: label alone on a line without a colon might be in error", \ "tmp.asm:4: error: invalid combination of opcode and operands", \ "tmp.asm:7: fatal: unable to open include file `bar.asm'" \ ])