Grafted from c80083ad142d.

Based on patches by Christian Heimes and Vajrasky Kok

This test requires the ifconfig executable on $PATH, /sbin/, or /usr/sbin.

of the time.  Patch by Julian Gindi.

virtual interface.  Original patch by Kent Frazier.

Issue #19638: Raise ValueError instead of crashing when converting billion character strings to float.

used in the "does the value get passed in properly" test.

compiled on a system with SO_REUSEPORT defined in the headers but run on
a system with an OS kernel that does not support that new socket option.

Document that @property can incorporate a docstring from the getter method.  Improve readabilty with additional whitespace.

big-endian platforms.

Temporary forbidden test_unseekable_incompleted_write fornot compressed 16-
and 32-bit wave file  on big-endian platforms.

Backport from 3.3 6e5afeada7ca.