Ale does not always indicate an error when compilation fails. AFAICT, the reason is that ALE's parser can't find a reference to the current file in the compiler's error messages. This is because either the current file is not mentioned in compiler output, or, it is mentioned but not in a way the Ale parser recognizes. In such instances I can see that compilation failed by looking at
My question is not about how to get an error marker at the correct line. Instead, I would like to know the fastest and simplest way to get Ale to indicate that some error occurred (i.e. it doesn't know what line in the current file to associate the error with).