Matchers: Error annotations catch things that are not errors and not even in Go code

Consider the (totally valid) makefile:

all: foo
	echo Done

include Foo.mk

Foo.mk:
        printf 'foo:\n\techo foo\n' > $@

On the first run of make, this generates

Makefile:4: Foo.mk: No such file or directory
printf 'foo:\n\techo foo\n' > Foo.mk
echo foo
foo
echo Done
Done

There isn’t really a good way to suppress this warning (see this StackOverflow question I asked) without massively complicating the Makefile. I don’t mind seeing this warning on the first make. However, my github actions go job decides that this is an error (it’s not; it’s non-fatal), and annotates every single pull request on my repository with an error on the relevant line on the Makefile. Please fix the annotation to not do this.

[JasonGross]

Seems to work well, thanks!

[bryanmacfarlane]

I think the solution is to have a much tighter regex for compile errors and then if there’s things it misses, problem matchers supports having multiple matchers.

I’ll have a PR soon for the v2-beta lineage.