CVS 1.12.13 hangs when getting gnulib

[Paul Eggert]

Here's how I can easily reproduce the bug:

   $ rm -fr gnulib
   $ cvs -z3 -d:pserver:anonymous@cvs.savannah.gnu.org:/sources/gnulib co gnulib
   cvs checkout: Updating gnulib
   U gnulib/COPYING
   U gnulib/ChangeLog
   ...
   U gnulib/tests/test-stpncpy.c
   U gnulib/tests/test-stpncpy.out.aix433
   U gnulib/tests/test-stpncpy.out.glibc

At this point CVS hangs.

I've reproduced the problem both in Debian GNU/Linux 3.1 x86, and on
Solaris 8 (sparc, 64-bit).

The problem does not occur with CVS 1.12.9 (as packaged by Debian
stable).

If I run CVS under "strace" on Debian, it works, so possibly it's a
timing-relating issue.