Re: Automake's file locking (was Re: Autoconf/Automake is not using version from AC_INIT)

[Bob Friesenhahn]

On Thu, 28 Jan 2021, Nick Bowler wrote:
> If I understand correctly the issue at hand is multiple concurrent
> rebuild rules, from a single parallel make implementation, are each
> invoking autom4te concurrently and since file locking didn't work,
> they clobber each other and things go wrong.

That is what would happen, but what currently happens is if the file 
locking does not work and a parallel build is used, then Autotools 
reports a hard error:

CDPATH="${ZSH_VERSION+.}:" && cd /home/bfriesen/src/graphics/GM && 
/bin/sh '/home/bfriesen/src/graphics/GM/config/missing' aclocal-1.16 
-I m4
autom4te: cannot lock autom4te.cache/requests with mode 2: Invalid 
argument
autom4te: forgo "make -j" or use a file system that supports locks
aclocal-1.16: error: autom4te failed with exit status: 1
gmake: *** [Makefile:4908: /home/bfriesen/src/graphics/GM/aclocal.m4] 
Error 1

In my case there is only one active developer so there would not be 
actual corruption.

Bob
--
Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
Public Key,     http://www.simplesystems.org/users/bfriesen/public-key.txt