glibc 2.15 has prlimit64, has an unsetenv that's declared nonnull,
and hasn't fixed the problems we were having trying to use the
POSIX strerror_r in C++ code.
Change-Id: I834356a385e5ae55500bd86781691b6c1c9c8300
We already had the POSIX strerror_r, but some third-party code defines
_GNU_SOURCE and expects to get the GNU strerror_r instead.
This exposed a bug in the libc internal logging functions where unlike
their standard brethren they wouldn't return the number of bytes they'd
have liked to have written.
Bug: 16243479
Change-Id: I1745752ccbdc569646d34f5071f6df2be066d5f4
