[racket] Building on Mac OS X 10.7 Lion (Developer Preview 3)

I can’t coerce the latest Racket source, from GitHub, to compile on
Lion. I wasn’t sure whether to build as 32-bit or 64-bit, so I tried
both. Here’s all of the relevant output, both the stdout from the
compilation process and the resultant crash report/core dump:

HEAD (@70b0eb8) as 32-bit: https://gist.github.com/960017
HEAD (@70b0eb8) as 64-bit: https://gist.github.com/960028
v5.1.1 release as 32-bit: https://gist.github.com/960045
v5.1.1 release as 64-bit: https://gist.github.com/960052

Any help would be appreciated, I’m excited to start playing with Racket. (-: