Sometimes building or running a program will fail due to bugs in the system API implementation (in glibc and the Hurd). Make sure you check this list and know them before porting, otherwise you'll end up debugging something just to find out its an already known bug.
Taken from the bug lists in Debian BTS. If you find more of them (and it is clear in the bug log that it is a bug), please add them to the list below.
These are the known system API limits that have porting implications.
msgget IPC not implemented
sockaddr_un.sun_path can't be assigned a
const char * when compiling with g++
breaks: fam, gail
status: maybe this should be in (see long bug log)
F_GETLK not implemented (
breaks: gnome-session (and others) from running
error: misc lock-related errors