[Libguestfs] [PATCH v2 0/2] lib: Allow db_dump package to be a weak dependency

Previously posted: https://www.redhat.com/archives/libguestfs/2017-October/msg00032.html This takes a completely different approach. It turns out that POSIX / the shell already defines a special exit code 127 for ‘command not found’. We can make a small adjustment to lib/command.c to return this exit code in that case. Then we just have to modify the db_dump code to test for this exit code. I also made db_dump unconditional, allowing the packager to either build without db_dump present at all, and/or to make db_dump into a weak runtime dependency which will be silently ignored if not present by the mechanism above. Rich.