Re: fix build failure during "make distcheck"

[Jose E. Marchesi]

Hi Bruno.

    There are three possible fixes to this situations:
    
    (a) List only individual files in EXTRA_DIST. Enumerate them! Then you don't
        need to worry about garbage files (editor backups, core dumps, whatever)
        getting accidentally packaged in the tarball.
    
    (b) Use a dist-hook to remove unnecessary files from a distribution. See
        
https://www.gnu.org/software/automake/manual/html_node/The-dist-Hook.html
    
    (c) List only individual files in EXTRA_DIST, for directories that may 
contain
        built files. For directories that contain only data files, list the
        directory, but use 'git status' to make sure the directory contains no
        extra / garbage files.
    
    Here are two patches, that implement (a) or (c), respectively. Either fixes
    "make distcheck". My preference is (a), since it's
      - the safest and
      - consistent with uses of EXTRA_DIST in other GNU packages.

I agree that (a) is the best way to go.
OK for master.

It would be good to have a reminder in HACKING to add new tests to
EXTRA_DIST.

Thanks!