The FreeBSD-specific pdfork() code in forkfd_freebsd.c code was failing to build because convertForkfdWaitFlagsToWaitFlags() wasn't defined. That function is behind a check for #ifdef HAVE_WAITID, which is only defined if _POSIX_VERSION is 2008 or later. That macro has been stuck at 2001 for the past 23 years. I can't explain how this code compiled with FreeBSD 14.1 and earlier, because I am sure it was using pdfork(). So just #define HAVE_WAITID for FreeBSD. It must have been there since much earlier than 13.0, but that seems like a reasonable starting point today. We also need to #include <sys/param.h> to have the __FreeBSD_version__ macro, something that also wasn't needed in earlier versions. It was probably indirectly #include'd by something. Pick-to: 6.8 6.9 Change-Id: I262d9922128d046221b7fffd0ec481bc0012f55c Reviewed-by: Thiago Macieira <thiago.macieira@intel.com> Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>