Re: --gnits, AC_INIT and VERSION

[Ralf Wildenhues]

Hello Robert, and sorry for not replying on this earlier:

* Robert Collins wrote on Wed, Sep 23, 2009 at 10:03:42AM CEST:
> There was discussion about getting version numbers from VCS recently;
> I've done a slightly different thing for a while now:
> AC_DEFUN([SUBUNIT_MAJOR_VERSION], [0])
> AC_DEFUN([SUBUNIT_MINOR_VERSION], [0])
> AC_DEFUN([SUBUNIT_MICRO_VERSION], [2])
> AC_DEFUN([SUBUNIT_VERSION],
> [SUBUNIT_MAJOR_VERSION.SUBUNIT_MINOR_VERSION.SUBUNIT_MICRO_VERSION])
> AC_PREREQ([2.59])
> AC_INIT([subunit], [SUBUNIT_VERSION], [contact...])
> AC_SUBST([SUBUNIT_MAJOR_VERSION]) ...
> 
> This works well, until gnits is added to AM_INIT_AUTOMAKE.
> 
> It looks like it expects a literal, not a macro in AC_INIT ?

Yeah, the test unfortunately needs the version number literally at m4
time; you can achieve that with something like

m4_define([SUBUNIT_MAJOR_VERSION], [0])
m4_define([SUBUNIT_MINOR_VERSION], [0])
m4_define([SUBUNIT_MICRO_VERSION], [2])
m4_define([SUBUNIT_VERSION],
         
m4_defn([SUBUNIT_MAJOR_VERSION]).m4_defn([SUBUNIT_MINOR_VERSION]).m4_defn([SUBUNIT_MICRO_VERSION]))
AC_PREREQ([2.59])
AC_INIT([subunit], m4_defn([SUBUNIT_VERSION]), [contact...])

BTW, and this is why I'm adding bug-autoconf here: Not changing the
AC_DEFUNs here to m4_define causes Autoconf 2.65 to barf with
  configure.ac:7: error: m4_divert_push: cannot change diversion to `GROW' 
inside m4_expand

which seems a bit surprising to me.  What's the NEWS entry that
described this change in behavior?  Or was that always problematic
and we only didn't notice earlier by chance?

Thanks,
Ralf