pkg/51972: pyexpat.so is missing from python27 installation.

[liman%cafax.se@localhost]

>Number:         51972
>Category:       pkg
>Synopsis:       pyexpat.so is missing from python27 installation.
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Feb 15 09:00:00 +0000 2017
>Originator:     Lars-Johan Liman
>Release:        pkgsrc-current
>Organization:
Cafax AB
>Environment:
Darwin <hostname> 16.4.0 Darwin Kernel Version 16.4.0: Thu Dec 22 22:53:21 PST 2016; root:xnu-3789.41.3~3/RELEASE_X86_64 x86_64
>Description:
The binary Python pkg packages for 2.7.13 do not contain the
file

lib/python2.7/lib-dynload/pyexpat.so

for some unknown reason.

It _does_ exist in the 2.7.12 binary packages.

It has been removed from the PLIST.common file, but it is
not obvious why.

It causes problems, as it is required by the get-pip.py
program, which installed the pip package maintainer for
Python, which is, in turn, a very often used utility.

(And yes, you can use py27-pip from pkgsrc, but I'm sure
there are other apps that need pyexpat.so as well.)
>How-To-Repeat:
Install python27 from binary packages.
>Fix:
Not quite sure. I haven't tried building from source, but
either not listing it in PLIST.common is a sheer mistake, or
it doesn't build cleanly, which possibly isn't detected, and
the file therefore doesn't apprear when one does "make
install", and is then not picked up by some automagic script
that combes the system for new installs.