bug#9037: distcheck should check for missing m4 files too

[Stefano Lattarini]

Hello automakers, and sorry for the delay.

References:

<http://debbugs.gnu.org/cgi/bugreport.cgi?bug=9037>

<http://debbugs.gnu.org/cgi/bugreport.cgi?bug=9026>

On Saturday 09 July 2011, Stefano Lattarini wrote:

> On Saturday 09 July 2011, Peter Johansson wrote:

> > Hi Bruno,

> >

> > On 7/8/11 5:24 PM, Bruno Haible wrote:

> > > +If you are using GNU @code{automake} 1.10 or newer, it is even easier:

> > > +Add the line

> > > +

> > > address@hidden

> > > +ACLOCAL_AMFLAGS = --install -I m4

> > > address@hidden example

> > > +

> > > address@hidden

> > > +to your top level @file{Makefile.am}, and run @samp{aclocal --install -I m4}.

> > > +This will copy the needed files to the @file{m4/} subdirectory automatically,

> > > +before updating @file{aclocal.m4}.

> > > +

> > I used to do this as it is an easy way to stay up to date with 3rd party

> > m4 files. I stopped doing this, however, after Ralf Wildenhues made me

> > aware there is a risk doing so. The risk is that aclocal will copy 3rd

> > party m4 files into m4 not only for you but also for your users if they

> > happen to run aclocal. Say, e.g., that a user want to build a somewhat

> > old version of your package from git; he bootstraps and as he has newer

> > versions of the m4 files available on his system aclocal copies them

> > into m4, which may cause problems as they are not necessarily compatible

> > with your configure.ac. To avoid this from happen, I've removed the

> > --install flag from my packages and calls aclocal --install -I m4

> > frequently instead.

> >

> Oh, good point, I hadn't thought about the precise semantics of `--install'

> when I wrote my answer.

>

> > There is, obviously, a risk doing this way, as mentioned above in this

> > thread, because if I'm not careful I may release a tarball with missing

> > m4 files. Would distcheck detect a missing m4 file, or would it be

> > possible to modify distcheck so it could warn about this case?

> >

> I think improving distcheck to catch such an error would be worthwhile.

>

OK, I've managed to come up with a test case that demonstrates how one can

use a "distcheck-hook" to diagnose this kind of errors. I'm not sure if

this should integrated into the automake-generated distcheck recipe proper

(maybe only when a new automake option, say "check-m4-distribution", is

used?), or if we should report Peter's description of the potential

problems with `--install' in the manual, and add our distcheck-hook there

in a new example (to be kept synced with the new testcase).

Opinions?

Regards,

Stefano

distcheck-m4.test
Description: application/shellscript