Bug#527589: libc0.3-dev: macros __CPU_ZERO_S, __CPU_SET_S etc. undefined [hurd-i386]
Looking through the build log of erlang on hurd-i386 architecture
I've found that the build is failed because macros __CPU_ZERO_S,
(which are defined in /usr/include/bits/sched.h for all other
architectures) are undefined, though /usr/include/sched.h uses them.