GRRR. I just found that XFree86.spec is missing a libtool BuildRequires. Rebuilding...
All of the build requirements in XFree86.spec are given as BuildPreReq's. What's the difference?
From what I can tell, BuildPreReq is deprecated, and should be replaced with BuildRequire.
http://www.geocrawler.com/archives/3/87/1999/7/50/2480267/
-Dave