We have very old FreeBSD build systems (6.3) which we use to maintain backwards compatibility with the system libraries for our proprietary binaries and avoid building on each and every FreeBSD version.
Question: Is it technically possible to install a fresh FreeBSD 11.x and jail the old system on it? Or will there be issues due to incompatible system calls?
I think to remember some - supposedly breaking - change of the kernel interface with respect to the size of
time_t or so. Are there any such changes that would break old binaries relying on the old syscall or would that merely affect newly built/linked binaries which are tied to the (corresponding) new syscall?