Crazy MacOS Header Values
For a while now, I've been getting horrible errors whenever I compile some package on my MacOS X machine. Some of the errors were of the form, MAC_OS_X_VERSION_MIN_REQUIRED must be <= MAC_OS_X_VERSION_MAX_ALLOWED. Others were complaining about some precompiled header being out of date.
It turned out that I had an environment variable, MACOSX_DEPLOYMENT_TARGET set to 10.3. I'd set this a long time ago because it alleviated problems that I seemed to have with every Perl module I tried to install.
I unset MACOSX_DEPLOYMENT_TARGET and ran the magical sudo fixprecomps. This fixed it.