Re: [PATCH] tests: introduce test_unset_prereq, for debugging

SZEDER Gábor [off-list ref] writes:

quoted

For convenience, the following two methods are now supported ways to
pretend that a prereq is not met:

	test_set_prereq !GPG

and

	test_unset_prereq GPG

I'm not sure this is the right way to do this.

I wanted to run the whole test suite with all GPG tests skipped the
other day.  With this 'test_unset_prereq' I would have to modify all
test scripts containing tests depending on the GPG prereq and add
'test_unset_prereq GPG', right?

Excellent point.  This won't cover that use case well.

That does not mean this change is useless.  If you are focusing on
developing a single test script, you can afford to tentatively add
these set/unset, just like you tentatively debug with echo's ;-)

But I find your SKIP_PREREQS an excellent idea.

It may want to be FORCE_PREREQS that lets you pretend a prereq is
not satisfied on your machine even when it actually is, and also
lets you pretend a prereq is satisfied on your machine even when it
is not.  SKIP_PREREQS would only do the first half, which would be
sufficient most of the time, though.

I think we would be better served by an environment variable similar
to $GIT_SKIP_TESTS, e.g. $GIT_SKIP_PREREQS, to list all the prereqs
that should be skipped even if they were met.