The Xrender package now requires an x11.pc file in your pkg-config path in order
for configure to complete.
This means that the user either needs to rebuild the versions of the X libraries
available from freedesktop.org, or write an x11.pc file (error prone).
As Xrender is a prerequisite for building Xft (which in turn is a prerequisite
for GTK), it would be nice to reduce the number of libraries a user will need to
(re)build in order to use apps on older systems.
It would be better if Xrender would fall back to the standard autoconf checks
for the X libraries if the x11 pkg-config file can't be found.
It looks to me like it checks for X with AC_PATH_XTRA if x11.pc doesn't exist...
See bug #122
I just tried building things again, and it seems to work.
I was basing this bug report off a jhbuild bug report I had received. I should
have checked things a bit more before filing.