bug#9026: [PATCH] aclocal: handle ACLOCAL_PATH environment variable

[Paolo Bonzini]

On 09/20/2011 12:51 PM, Stefano Lattarini wrote:
> >  Yes (and that's on purpose: ACLOCAL_PATH is typically used by a user
> >  which has newer versions of libraries installed, so they need their
> >  directories to override everything).
>
> Yes, this might be desirable.  But then, for consistency sake, shouldn't
> we allow the .m4 files in the default system acdir and in the directories
> added through a `dirlist' file to override the automake macros as well?

Yeah, I think the problem is that in the normal search path (from 
`aclocal -I /foo -I /bar'):

  1. `/foo'

  2. `/bar'

  3. ACDIR-APIVERSION

  4. ACDIR

The directories from dirlist and ACLOCAL_PATH should go after (3), 
rather than after (4).  Perhaps even after (2).

> I'm not sure about this, it has its pros and cons...  Anyway, if we decide
> to go down this road, we should wait for 1.12, as the introduction of such
> a backward-incompatibility, albeit limited, is inappropriate for a minor
> release such as 1.11.2.

You could certainly push your patch now and modify the behavior of both 
dirlist and ACLOCAL_PATH in 1.12.

I doubt there are many dirlist users anyway, so the probability of 
regressions should be quite low.

Paolo