fix build failure during "make distcheck"

[Bruno Haible]

Hi,

There is currently a build failure during "make distcheck":

Making check in testsuite
make[2]: Entering directory '/POKE/poke/poke-0.1-beta/_build/sub/testsuite'
Making check in poke.libpoke
make[3]: Entering directory 
'/POKE/poke/poke-0.1-beta/_build/sub/testsuite/poke.libpoke'
make  values
make[4]: Entering directory 
'/POKE/poke/poke-0.1-beta/_build/sub/testsuite/poke.libpoke'
/bin/bash ../../libtool  --tag=CC   --mode=link gcc  -g -O2   -o values  
values-values.o ../../gl/libgnu.la ../../libpoke/libpoke.la 
libtool: link: gcc -g -O2 -o .libs/values values-values.o  
../../gl/.libs/libgnu.a -lreadline ../../libpoke/.libs/libpoke.so 
-L/POKE/poke/poke-0.1-beta/_build/sub/jitter/lib -lgc -pthread -Wl,-rpath 
-Wl,/POKE/poke/poke-0.1-beta/_inst/lib
gcc: error: values-values.o: No such file or directory
make[4]: *** [Makefile:1764: values] Error 1
make[4]: Leaving directory 
'/POKE/poke/poke-0.1-beta/_build/sub/testsuite/poke.libpoke'
make[3]: *** [Makefile:1907: check-am] Error 2
make[3]: Leaving directory 
'/POKE/poke/poke-0.1-beta/_build/sub/testsuite/poke.libpoke'
make[2]: *** [Makefile:1773: check-recursive] Error 1
make[2]: Leaving directory '/POKE/poke/poke-0.1-beta/_build/sub/testsuite'

What happens is that

  1) Because testsuite/Makefile.am defines EXTRA_DIST to contain the 
directory(!)
     poke.libpoke, the distribution tarball contains all files of this 
directory.

  2) Since my initial build is a build in srcdir, it contains also the
     values-values.o file. Look:

     $ tar tf poke-0.1-beta.tar.gz |grep '\.o$'
     poke-0.1-beta/testsuite/poke.libpoke/values-values.o
     poke-0.1-beta/testsuite/poke.mi-json/mi_json-mi-json.o

     $ tar tf poke-0.1-beta.tar.gz |grep '\.libs'
     poke-0.1-beta/testsuite/poke.libpoke/.libs/
     poke-0.1-beta/testsuite/poke.libpoke/.libs/lt-values
     poke-0.1-beta/testsuite/poke.libpoke/.libs/values
     poke-0.1-beta/testsuite/poke.mi-json/.libs/

  3) "make distcheck" executes a VPATH build. It finds the values-values.o file
     already present in the srcdir, therefore does not build it in the builddir.
     The link command line then fails.

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.

0001-Fix-build-failure-during-make-distcheck-alt1.patch
Description: Text Data

0001-Fix-build-failure-during-make-distcheck-alt2.patch
Description: Text Data