Currently, 'nix-daemon --stdio' is always failing for me, due to the
splice call always failing with (on a 32-bit host):
splice(0, NULL, 3, NULL, 4294967295, SPLICE_F_MOVE) = -1 EINVAL (Invalid argument)
With a bit of ftracing (and luck) the problem seems to be that splice()
always fails with EINVAL if the len cast as ssize_t is negative:
http://lxr.free-electrons.com/source/fs/read_write.c?v=4.4#L384
So use SSIZE_MAX instead of SIZE_MAX.