I noticed that nanosleep() on 64 bit, "only" supports 292 years,
rather than the full potential 292 billion years with 64 bit time_t, due to:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/include/linux/time.h?id=refs/tags/v3.16#n87

Attached is a program from Paul Eggert that illustrates the bug.
Running this program on a buggy host outputs something like this:

  Setting alarm for 1 second from now ...
  Sleeping for 9223372036854775807.999999999 seconds...
  After alarm sent off, remaining time is 9223357678.462306617 seconds;
  i.e., nanosleep claimed that it slept for about 293079448610.606445 years.

Gnulib-using applications have a workaround for this bug, but a workaround
shouldn't be necessary.  For what it's worth, the bug is fixed in Solaris 11 (x86-64),
though it's present in Solaris 10 (64-bit sparc).

thanks,
Pádraig.