[Dune] Autotools build system, minimum requirements

[Bård Skaflestad]

Dear Dune,

I was trying to set up a build (based on the Autotools) of the current
development sources (versions listed below) on a CentOS 5.9 system.

Now, had I read the installation notes and system requirements on
http://www.dune-project.org/doc/installation-notes.html more thoroughly
beforehand I would not have tried because that clearly states Autoconf
>= 2.62 as a minimum requirement whereas my CentOS 5.9 system only
features Autoconf 2.59.

I'll solve that locally, but the bigger issues is that there seems to be
a little confusion and/or inconsistency in the way the minimum
requirements are encoded in the configure.ac and *.m4 files.  Searching
through the source trees I can only find

        AC_PREREQ([2.50])

(with and without the quotes) including in "duneproject" but not in
dunecontrol's DUNE_AC_INIT macro.  Is not encoding the actual minimum
requirements an oversight or a conscious decision?

For the record, the first build obstacle I encountered that is
definitely related to minimum Autoconf version was the unconditional use
of AC_PROG_MKDIR_P (introduced, as far as I can tell, in dune-common's
commit 6f87a45).  I haven't been able to trace the history of that
macro, but it was *definitely* introduced after Autoconf 2.59.


Sincerely,
-- 
Bård Skaflestad
SINTEF ICT, Applied Mathematics


List of "master" versions in the modules I tried to build:

./dune-common/bin/dunecontrol git rev-parse --short --verify HEAD
--- going to build dune-common dune-istl dune-geometry dune-grid  ---
--- calling git for dune-common ---
a29299b
--- dune-common done ---
--- calling git for dune-istl ---
4acfda1
--- dune-istl done ---
--- calling git for dune-geometry ---
47eb5f9
--- dune-geometry done ---
--- calling git for dune-grid ---
65581e4
--- dune-grid done ---
--- done ---