From: Tom Lane <tgl@sss.pgh.pa.us>
To: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
cc: Noah Misch <noah@leadboat.com>, Andrew Dunstan <andrew@dunslane.net>,
        pgsql-hackers@postgresql.org
Subject: Re: PL_stashcache, or, what's our minimum Perl version?
In-reply-to: <7fbd4508-23c5-f426-d374-6c72e20bbce9@2ndquadrant.com>
References: <20540.1501210115@sss.pgh.pa.us> <16894.1501392088@sss.pgh.pa.us>
 <20170730154814.GA2636941@rfd.leadboat.com> <22744.1501430710@sss.pgh.pa.us>
 <20170730163054.GA2630977@rfd.leadboat.com> <25937.1501433410@sss.pgh.pa.us>
 <c3ad3515-64e9-f5a1-1f39-d2cb646fcb96@2ndquadrant.com>
 <9072.1501527316@sss.pgh.pa.us>
 <90a92a7d-938e-507a-3bd7-ecd2b4004689@2ndquadrant.com>
 <14432.1501529890@sss.pgh.pa.us>
 <7fbd4508-23c5-f426-d374-6c72e20bbce9@2ndquadrant.com>
Comments: In-reply-to Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
	message dated "Mon, 31 Jul 2017 16:22:43 -0400"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <18304.1501534485.1@sss.pgh.pa.us>
Date: Mon, 31 Jul 2017 16:54:45 -0400
Message-ID: <18305.1501534485@sss.pgh.pa.us>
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org

Peter Eisentraut <peter.eisentraut@2ndquadrant.com> writes:
> On 7/31/17 15:38, Tom Lane wrote:
>> Really?  That seems pretty broken, independently of how many variables
>> are affected.  But the ones you'd be most likely to do that with are
>> using AC_PATH_PROG already, I think.  Having lesser-used program variables
>> behave inconsistently doesn't seem like much of a win.

> Well, if we're fiddling around here, I would change them all to
> AC_CHECK_PROG if possible.  Especially the PYTHON one annoys me all the
> time.  CC is another one I set occasionally.

I will object really really strongly to that, as it is 180 degrees from
where I think we need to go, and will make things a lot worse than before
on the documentation aspect that I was concerned about to begin with.

If we need to fix things so that AC_PATH_PROG will honor a non-path
input value, then let's do that.  But let's not make the build system
shakier/less reproducible than it is already.

I suggest that we could inject logic like this:

  if VARIABLE-is-set-and-value-isn't-already-absolute; then
    VARIABLE=`which $VARIABLE 2>/dev/null`
  fi

in front of the existing logic for AC_PATH_PROG(VARIABLE,...).
Maybe "which" isn't the best tool for the job, not sure.

Another idea, which would probably require replacing _AC_PATH_PROG
rather than just putting a wrapper around it, would be to let it
perform its normal path walk but using the given word instead of
$ac_word.

			regards, tom lane


-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers