Re: (toplevel) introduce host subdir configuration in Makefile

Thomas Dickey
2002-12-02T22:03:10Z

On Mon, Dec 02, 2002 at 02:39:49PM -0200, Alexandre Oliva wrote:
> On Dec 2, 2002, Daniel Jacobowitz <drow@mvista.com> wrote:
>
> > You may already know this, but just to be careful I'll mention it
> > anyway... it is not necessarily safe to configure more than one
> > subdirectory at a time. One possibly gotcha is the updating of
> > $cache_file. It isn't done atomically and so if you happen to have two
> > subdirectories with the same (essentially) configure.in, and they
> > happen to get started on an SMP system by make -j2 at (essentially) the
> > same time, you can blow out the cache file.
>
> > This isn't entirely hypothetical. A similar thing happened in
> > libiberty with two invocations of config.status.
>
> This was a bug in autoconf 2.13, that's fixed in autoconf 2.5x.

arguable (as usual). 2.13 didn't pretend to support parallel make.
2.5x pretends to, but (as you note) config.cache isn't handled.
So it appears more as a bug in 2.5x

--
Thomas E. Dickey <dickey@invisible-island.net>
http://invisible-island.net
ftp://invisible-island.net