Re: Weird error messages with duplicate AC_OUTPUT entries

[Akim Demaille]

| Hi,
| When a configure.ac contains duplicate entries in its AC_OUTPUT,
| running autoconf-2.53c generates bizarre error messages:
| 
| # cat configure.ac
| AC_PREREQ(2.53c)
| AC_INIT([hello],[0.0])
| AC_CONFIG_SRCDIR([hello.c])
| AM_INIT_AUTOMAKE([foreign])
| AC_PROG_CC
| AC_PROG_RANLIB
| AC_CONFIG_FILES([Makefile Makefile])
| AC_OUTPUT
| 
| # aclocal
| # autoconf
| configure.ac:7: error: `Makefile' is already registered with
| AC_CONFIG_FILES.
| /usr/src/packages/BUILD/autoconf-2.53c/lib/autoconf/status.m4:844:
| AC_CONFIG_FILES is expanded from...
| configure.ac:7: the top level
| autom4te: /usr/bin/m4 failed with exit status: 1

Arg.  You are right, this is not very nice :(

| Also note: This also exposes a path from autoconf's the directory where
| autoconf had been build. This directory is completely meaningless (and
| not available) to users if using a installed copy of autoconf.

This is right too, but I see no means to solve this issue, unless when
freezing, m4 decides to ``update'' the location of these files.
That's an approximation, agreed, but one of the less false I can
imagine :)