Re: pg_upgrade test writes to source directory

On 31.05.22 09:17, Michael Paquier wrote:
> On Sat, May 28, 2022 at 04:14:01PM -0400, Tom Lane wrote:
>> Yeah, I'd noticed the obsoleted comments too, but not bothered to complain
>> since that was just WIP and not an officially proposed patch.  I'll be
>> happy to review if you want to put up a full patch.
> Well, here is a formal patch set, then.  Please feel free to comment.
> 
> FWIW, I am on the fence with dropping TESTDIR, as it could be used by
> out-of-core test code as well.  If there are doubts about
> back-patching the first part, doing that only on HEAD would be fine to
> fix the problem of this thread.

I don't understand the point of this first patch at all.  Why define 
TESTOUTDIR as a separate variable if it's always TESTDIR + tmp_check? 
Why define TESTOUTDIR in pg_regress invocations, if nothing uses it?  If 
you want it as a separate variable, it could be defined in some Per 
utility module, but I don't see why it needs to be in Makefile.global. 
What is the problem that this is trying to solve?