Before: call ale#assert#SetUpLinterTest('lua', 'luac') After: call ale#assert#TearDownLinterTest() Execute(The default command should be correct): AssertLinter 'luac', ale#Escape('luac') . ' -p - ' Execute(The luac executable should be configurable): let g:ale_lua_luac_executable = 'luac.sh' AssertLinter 'luac.sh', ale#Escape('luac.sh') . ' -p - '