Stop installing multiple copies of the shared library.

[bodea]

This is never linked into programs by ld, so the symlink redirections from .so
and soname are not required. Moreover, the Debian package was ending up with
three copies of the same file (rather than one file and two symlinks).

The only copy will be installed as libnss_cache.so.2, to meet the API for NSS
which expects to load libnss_<service>.so.<x>, where x is 2 for glibc 2.1 and
later (see nsswitch.conf(5)).

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[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 58.80%. Comparing base (08c9bc4) to head (5824715).
Report is 20 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main      #76       +/-   ##
===========================================
- Coverage   69.97%   58.80%   -11.17%     
===========================================
  Files           2        2               
  Lines         403      403               
  Branches       26       87       +61     
===========================================
- Hits          282      237       -45     
  Misses        100      100               
- Partials       21       66       +45     

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[kev009]

This might have been too eager, I am fine with just one library but maybe we need to continue using the SONAME variable?

Warning: pkg(8) will not register it as being provided by the port.
Warning: If another port depend on it, pkg will not be able to know where it comes from.
Warning: It is directly in /usr/local/lib, it is probably used by other ports.```

[bodea]

A SONAME is only required when linking via a libnss_cache.so symlink, so that the linker writes libnss_cache.so.2 into the binary rather than the path name. We're not providing such a symlink, so it is not necessary. If someone were to link to the library for some reason, that would require passing using the full path (rather than using -lnss_cache), in which case the linker records that path correctly.

[kev009]

A SONAME is only required when linking via a libnss_cache.so symlink, so that the linker writes libnss_cache.so.2 into the binary rather than the path name. We're not providing such a symlink, so it is not necessary. If someone were to link to the library for some reason, that would require passing using the full path (rather than using -lnss_cache), in which case the linker records that path correctly.

Empirically it seems to be used by the pkg system. Can it not be set to the same file name?

[kev009]

Who even are the people that approved and merged this with no history with the repo. Typical abysmal Google engineering quality...

This is a standard Debian lint as well https://lintian.debian.org/tags/sharedobject-in-library-directory-missing-soname.html