[racket-dev] make gets hung up building documentation

Fresh git checkout of racket.  Ran make at 6am.  Flew to Lock Haven for pancake breakfast fly-in.  Flew back.  Went to church.  Came back.  make not done.  Took a nap.  8+ hours since I started, make stuck at the same place:

[...]
raco setup: 6 running: <pkgs>/xrepl-doc/xrepl/xrepl.scrbl
raco setup: 3 running: <pkgs>/racket-index/scribblings/main/local-redirect.scrbl
raco setup: 3 running: <pkgs>/racket-index/scribblings/main/search.scrbl

ActivityMonitor says:

process-name: racket, %CPU: 100.0, cpu-time: 3:19:42.96 (and increasing), threads: 21, idle-wake-ups: 93

Any clues?  I did a ^C, restarted make, it blew through all the stuff it did before, and now is taking a long time building the documentation again, currently again at 100% CPU here:

raco setup: --- building documentation ---
raco setup: 7 running: <pkgs>/racket-doc/scribblings/guide/guide.scrbl

Machine is a MBP running OSX 10.9.2.

Geoff