Here's a patch that replaces the test for the pthread library with the
macro from
<http://www.gnu.org/software/ac-archive/htmldoc/acx_pthread.html>. The
patch appends acx_pthread.m4 to acinclude.m4 and replaces
AC_CHECK_LIB(pthread, ...) with ACX_PTHREAD in configure.in. Without
this patch Guile CVS cannot be built on FreeBSD. I've tested the patch
on Debian Sarge, Mac OS X, OpenBSD and FreeBSD 5.
pthread-check.diff