Is Pypy an option for running Waf builds now? While Pypy 2.0 beta 1 still hangs on simple parallel builds, Pypy nightly (59365-f2f4cb496c1c) seems to work much better now.

The numbers below represent the best times of 10 runs on a 64-bit Ubuntu 12.10 laptop. The typical benchmark project was used for this purpose (./utils/genbench.py /tmp/build 50 100 15 5):

cPython 2.7.3 pypy-c-jit pypy-c-nojit
no-op build 0.76s 6.5s 7.7s
full build 39s 45.4s 48.3s

The no-op build times represent the time taken to load the serialized Python data without executing any command. Pypy is still using a pure python implementation if pickle, which is likely to take much more time than the C extension present in cPython.

This can explain the time differences on the full build times. If we substract these values, we can imagine that the Pypy runtime is getting nearly as fast as cPython.