(If you fclose(3) rather than pclose(3) a FILE* you got from popen(3),
future popen(3)s fail obscurely, at least on Mac OS.)
(cherry picked from commit 2bf76e143da933184d1392fb9bea3a3896c37e76)
Change-Id: I5578fe06753061b0dbc5ee951ebf31eb2bab0389
This might not seem like much, but it's already better than Mac OS'
backtrace(3).
(cherry picked from commit 2a46f6293f19b9d6100187fbd53088088e671b88)
Change-Id: I197b06c4c19f728ad6f194b2f473bd9dcd99b8a6