bug#18109: 24.4.50; `compilation-error-regexp-alist-alist': wrong regexp for Maven

[Filipp Gunbin]

On 06/12/2020 16:05 +0100, Mattias Engdegård wrote:

> Thus it looks like we can expect exactly one space each after the first and 
> second colon and after the comma, instead of zero-or-more spaces (the '??' 
> comments above). As a Gradle user, can you confirm this?
>
> The way the pattern is written makes it prone to matching other messages 
> entirely or partly, with potential negative consequences for correctness, 
> performance or both.

It was me who put there those quantifiers, and I don't object to making
the regexps stricter.

But, we just need to be aware that Java tools usually don't expect the
output to be parsed.  Like, an IDE uses Gradle's API to run it, and
Gradle uses compiler API to compile - this way none of them have to
parse anything.  So they output something that can be parsed, yes, but
the format could change at any time.  That is why I'm more inclined to
making regexps more _lax_, not the other way around (and fix the
problems with them once they appear).

Filipp