Re: Bug#372179: marked as done (autoconf: AC_CANONICAL_SYSTEM overwrites $@)

[Ralf Wildenhues]

Getting bug-autoconf into play:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=372241
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=372179

> Date: Thu, 8 Jun 2006 20:09:30 +0200
> From: Julien Danjou <address@hidden>
> To: address@hidden
> Subject: apr-util: FTBFS: cannot stat `./debian/tmp/usr/include/apr-1.0': No 
> such file or directory

> Package: apr-util
> Version: 1.2.7-1
> Severity: serious

> There was a problem while autobuilding your package:

> > dh_install -a
> > cp: cannot stat `./debian/tmp/usr/include/apr-1.0': No such file or 
> > directory
> > dh_install: command returned error code 256
> > make: *** [binary-arch] Error 1

This is because the APR_PARSE_ARGUMENTS macro of apr-util parses the
configure arguments, very similar to what _AC_INIT_PARSE_ARGS does;
and AC_CANONICAL_SYSTEM now overwrites the positional parameters by
using
  set x ...


I could find an online copy of APR_PARSE_ARGUMENTS here:
http://apache.hpi.uni-potsdam.de/document/sources/httpd-2.0.45-html/source/build/apr_common.m4

A note to the apr people: several macros in Autoconf overwrite the
positional parameters, not just AC_CANONICAL_SYSTEM.  For example,
AC_CHECK_PROG does, so do some others.  There is really no guarantee
that $@ is conserved throughout the configure script.

IMHO the best would be to just document this limitation in the Autoconf
manual.  This would mean, however, that apr needs to rewrite its macros.
It may be possible to reorder macro invocations so the expansion of
APR_PARSE_ARGUMENTS comes before any AC_CANONICAL_*?

Thoughts?

Cheers,
Ralf