missing symbol clock_gettime after glib rebuild

[Britton Kerin <britton kerin gmail com>]

After recompiling my glib build I get failures like this when linking
against it:

     /home/bkerin/local/lib/libgthread-2.0.so: undefined reference to
`clock_gettime'

and gvim dies like this:

     gvim: symbol lookup error:
/home/bkerin/local/lib/libgthread-2.0.so.0: undefined symbol:
clock_gettime

I've run into this before and googled a lot but never found a fix that
worked.  Clues?

Thanks,
Britton