Re: maintainer mode parallel make issue

[Ralf Wildenhues]

Hi Eric,

thanks for the bug report.

* Eric Blake wrote on Thu, Apr 16, 2009 at 04:17:32PM CEST:
> I'm using origin/next at the moment, and seeing failures like this anytime I 
> touch configure.ac then attempt a parallel make on cygwin:

Do you see these failures with Automake 1.10.2 also?
Which Autoconf versions are you using?
Have you seen them on systems other than Cygwin?
How old is this Cygwin version?
Which Perl version do you have installed?
Which file system does this happen on?

> $ make -j2 check
> CDPATH="${ZSH_VERSION+.}:" && cd . && /bin/sh 
> /home/eblake/m4-patch/build-aux/missing --run aclocal-1.10c -I ltdl/m4
> CDPATH="${ZSH_VERSION+.}:" && cd . && /bin/sh 
> /home/eblake/m4-patch/build-aux/missing --run autoconf
>  cd . && /bin/sh /home/eblake/m4-patch/build-aux/missing --run automake-1.10c 
> --gnu
> /bin/sh ./config.status --recheck
> running CONFIG_SHELL=/bin/sh /bin/sh ./configure -C CC=ccache gcc 
> --disable-shared CFLAGS=-gdwarf-2 -Wall --enable-ltdl-convenience --no-create 
> --no-recursion
> configure: WARNING: unrecognized options: --enable-ltdl-convenience
> autom4te: cannot rename autom4te.cache/traces.1t as autom4te.cache/traces.1: 
> No such file or directory
> automake-1.10c: autoconf failed with exit status: 1
> make: *** [Makefile.in] Error 1

> Both autoconf and automake are stomping on the same autom4te.cache files, and 
> when one process completes sooner than the other, the second autom4te process 
> loses the battle.  Is this a bug in autom4te for not supporting autoconf and 
> automake in parallel, or is it a bug in automake for not serializing these 
> two 
> actions when it detects that a change in configure.ac requires rerunning both 
> autotools?

autoconf and automake are intended to be able to run in parallel, that's
what XFile::lock and its call in autom4te is for.

The above looks like XFile::lock fails to do its work.  We should have a
test that ensures that, in either Autoconf or Automake.

Hmm.  I've been running parallel make on Cygwin, and have never seen
such an issue before.

Cheers,
Ralf