The Setup.in entry is sort of a lie; it links with -lexpat, but
Expat's Makefile doesn't actually build a libexpat.a. I'll send
Expat's author a patch to do that; if he doesn't accept it, this
rule will have to list Expat's object files (ick!), or have a
comment explaining how to build a .a file.
Andrew M. Kuchling