bug#13514: unintentional regression with AC_CONFIG_MACRO_DIR in 1.13.1

[Stefano Lattarini]

On 02/04/2013 11:00 AM, Pavel Raiskup wrote:
>> [ ... ]
> 
> Ping.  Are you considering my opinions OK?
>
Basically yes; and a patch would obviously be welcome, if you want
to speed up the fixing of this bug ;-)

> Quickly again (let's say that AC_CONFIG_MACRO_DIR([m4]) is specified):
>   a) Warn because 'aclocal -I m4'
>
It should be just 'aclocal' here.  The point of the new code is that,
if you specify a directory as argument to AC_CONFIG_MACRO_DIR, you
don't need to repeat it again on the aclocal command line nor in
ACLOCAL_AMFLAGS anymore.

>      wants to search 'm4' dir which does not
>      exist.  Ignoring this completely is imo idea;
>
s/idea/bad idea/ here, I guess.  Right?  IF yes, I mostly agree.

[1] Run aclocal, then libtoolize (which might create the m4 directory),
    then run aclocal again.

>   b) Don't fail in that because it breaks autoreconf chain;
>
ACK.

>   c) Create the 'm4' directory in by autoreconf which is not necessary - but
>      it silences the warning. (And it "fixes" this problem also, as the
>      automake does not have a reason to fail).
>
This would probably require extra early tracing in autoreconf ...  And
it's something to be brought up on the autoconf list.

To summarize: for what concerns automake, I think degrading the fatal
error in aclocal to a warning is the best and safest approach for now.
Improvements or re-tightening can be done later, if needed.

Regards,
  Stefano