Re: Current trunk fails to build on MS-Windows

[Eli Zaretskii]

> Date: Wed, 14 Jan 2015 10:30:29 +0000
> From: Gavin Smith <address@hidden>
> Cc: Karl Berry <address@hidden>, address@hidden, address@hidden
> 
> >> A similar problem would be an update to configure.ac that couldn't be
> >> processed with older versions of autoconf. We can't check for versions
> >> of autoconf in the configure script, for example.
> >
> > Then perhaps always check and display a non-fatal warning, to the
> > effect that "Gawk >= 4.0 not found; regenerating texindex.awk will be
> > impossible", or some such.  I've seen several packages do that.
> >
> 
> I don't know. I thought of a similar situation that may shed light.
> Suppose there were Info files in a distribution that needed to be
> regenerated with makeinfo from certain versions from GNU Texinfo.
> Should the configure script check for this? This is similar to the
> gawk situtation, in that end users can still use the files
> (documentation files, or interpreted program).
> 
> It's not like checking for features in compilers, because we don't
> distribute the compiled output, so users would need a configure check
> to be able to use the program.
> 
> Changes to the build system are different as well, because it's absurd
> for the build system to be checking if it itself can be built.

But the problems you mention here are already solved, see
build-aux/missing.  And our Makefile's already call that script for
the likes of autoconf, automake, help2man, and yes, even makeinfo.
This is standard practice in the GNU project software and elsewhere.

We could do the same with Gawk 4.x, if that's more acceptable than a
configure-time test.

> If we were to check for gawk in the configure script, would this be a
> check on the output of "gawk --version"? It's often said that it's
> better to check for the features one needs instead of a particular
> version of a particular program. There might not be other Gawk/Awk
> implementations than GNU Gawk that have the needed features, though.
> (Same for a check on "makeinfo --version" for checks on the version of
> Texinfo.)

I think --version is sufficient in this case, as all of the features
weer introduced in 4.0.