I just merged in a change to git that tries to fix the parallel build problem without calling 'sync.' If you are one of our users who likes to work off git and builds in parallel ('make -jN' for N>1), we were having an issue of files not being ready while they were being parsed. See issue #478 on gnuradio.org for more details. The current version in git works for me on multiple machines, but I'd like more feedback if it's failing for anyone.