Pretty sure this memset call in pg_basebackup.c is incorrect, as it passes parameters in the wrong order:
MemSet(&stream, sizeof(stream), 0);
It seems benign, because we're setting all the fields explicitly, but gcc is nagging about it.
Indeed,that's backwards. Interestingly enough I thought I did a c&p between that and the one in pg_receivexlog.c, but clearly I did not. And my gcc did not nag about it.