How to ignore beginning of line in errorformat

Question

I have error or warning messages from some tool with the following format:

2022-08-18T21:25:01.972 WARNING ##]  file:///Users/myuser/somedir/file.txt:123: Error: something went wrong

One of the built-in error formats erroneously matched the leading timestamp and file:// as part of the file name. I need a format that ignores all of the stuff in the beginning but can’t come up with one. I don’t quite understand the advanced options from :h errorformat. The version I have is this but it of course includes the beginning of the line in the file name as well: %f:%l:\ %t%*\\a:\ %m.

How can I fix my errorformat so that only the actual file name is matched?

i.e. this: /Users/myuser/somedir/file.txt

Answer 1

You can use regular expressions as part of your errorformat definition.

See section Pattern matching under :help errorformat for more details on the exact syntax to use in errorformat specification, for example you want %.%# for the equivalent of the .* regular expression.

In your case, you can use:

%.%#]%\\s%#file://%f:%l:\ %t%*\\a:\ %m

This will skip everything up to ]\s*file:// (where the \s* part matches optional whitespace) and start matching the %f at that point.

(You can also try to incorporate the %t matcher in your expression, to capture the error type, which is WARNING in your example.)