[Python-Dev] Updating to autoconf 2.5x

[Guido van Rossum]

> Folks,
> 
> autoconf maintainers have advanced autoconf development over the last
> few years in slightly incompatible ways; as a result, the have
> produced autoconf 2.50 and successors.
> 
> The generated autoconf scripts vary largely in their text, and
> slightly in their behaviour; autoconf 2.50 offers many additional
> features, also, not all configure.in scripts work with autoconf 2.50.
> 
> Access to autoconf 2.13 with Linux distributions is becoming a
> problem, since some Linux distributors only offer 2.5x packages. So
> the question arises whether Python's configure should update to 2.50.
> 
> In rev 1.268, I had ported configure.in to support autoconf 2.50, but
> have continued to use autoconf 2.13 to regenerate it.
> 
> If all regular editors of configure.in have autoconf 2.5x available,
> or can install it, I'd propose to bump the AC_PREREQ to 2.50.
> 
> For those of you who'd then need both autoconf versions available, I
> can recommend the Debian wrapper; this is a perl script that invokes
> either autoconf2.13 or autoconf2.50, depending on several criteria
> (configure.in or configure.ac? AC_PREREQ?). If there is interest, I
> can post instructions on how to install both versions side-by-side.
> 
> So what do you think?
> 
> Regards,
> Martin

No problem from me.  autoconf 2.50 works perfectly for me.  But when I
downloaded and installed autoconf 2.53, this is what I got when I ran
it:

$ autoconf          
configure.in:1062: error: do not use LIBOBJS directly, use AC_LIBOBJ (see section `AC_LIBOBJ vs. LIBOBJS'

Autoheader gives me a bunch of new warnings:

$ autoheader
WARNING: Using auxiliary files such as `acconfig.h', `config.h.bot'
WARNING: and `config.h.top', to define templates for `config.h.in'
WARNING: is deprecated and discouraged.

WARNING: Using the third argument of `AC_DEFINE' and
WARNING: `AC_DEFINE_UNQUOTED' allows to define a template without
WARNING: `acconfig.h':

WARNING:   AC_DEFINE([NEED_MAIN], 1,
WARNING:             [Define if a function `main' is needed.])

WARNING: More sophisticated templates can also be produced, see the
WARNING: documentation.
autoheader: `pyconfig.h.in' is updated

Should we stick with 2.50, or make configure.in compatible with 2.53?

I do think that we should agree on using the same version of autoconf,
to prevent huge massive changes to the configure script each time
someone with a different version regenerates it.

--Guido van Rossum (home page: http://www.python.org/~guido/)