nis compat depreciation and test failures

[Florian Weimer]

On 08/14/2017 06:49 PM, Steve Ellcey wrote:
> I have a question about libnss_compat.  There was a change to nis/Makefile
> to stop building this library by default and only build it when configuring
> with --enable-obsolete-nsl.  However some glibc tests are still testing this
> library whether it is built or not.  In nss/spwd-lookup.c, nss/pwd-lookup.c,
> and nss/grp-lookup.c there is a definition of DEFAULT_CONFIG that includes
> 'compat' as a lookup method and that will cause some tests to try and load
> libnss_compat even when it has not been built.

Thanks for noticing this.  We should remove “compat” from the default
configuration and replace it with “files”, at least for the next
release.  For the 2.26 releases, we may have to make this conditional on
whether --enable-obsolete-nsl has been specified.

The default for the hosts database, "dns [!UNAVAIL=return] files" looks
wrong as well.  We should always prefer “files” (hopefully with entries
for localhost) over “dns”.

Thanks,
Florian