pthread_atfork()

[Samuel Thibault <samuel.thibault@ens-lyon.org>]

Hello,

At least in pike7.6, ./configure detects pthread_atfork() and then the
resulting program uses it, and fails because for now our implementation
is

return ENOSYS;

If we weren't providing the function, pike would manage to work without
it. So until we have a proper implementation maybe we should add a
debian patch that drops the function, so as to have circumvents such as
pike's enabled?

(people wouldn't expect such function to fail, so having a stub that
returns ENOSYS may be asking for troubles).

Samuel