Re: [PATCH] build: speed up configure for releases

[Jim Meyering]

Jim Meyering wrote:
> Eric Blake wrote:
>> At this point, we're pretty good about picking up gnulib dependencies
>> without having to be warned about them.  The time spent in configure
>> to check for declarations is pretty expensive, and really only needs
>> to be done by a maintainer every once in a while, rather than by
>> every downstream client on every configure run.
>>
>> * configure.ac (gl_ASSERT_NO_GNULIB_POSIXCHECK): Comment out,
>> with a note why.
>> ---
>>
>> I've been camping on this one for a long time; I guess it would be
>> even more impressive if I compared benchmark numbers of the timing
>> difference between using this patch and omitting it.
>
> I too have considered that.
> I could go either way, but would need the nudge of actual numbers.
>
> Since I rarely configure without using a cache, I suspect
> that the speed difference will be negligible for me.
>
> On the other hand, for most people, even a speed-up of just
> a few seconds would probably be welcome.
>
> How about a compromise: leave the code there, but guard it with
> some new envvar setting that is normally off.
> Then add something to my-distcheck so that for at least one
> ./configure run it is enabled.  That will preserve the safety net
> *and* save most people the cost of those added tests.

If you can do that, great, but even a note in README-release
would be sufficient.