The errors relating to r600 indicate it's having trouble converting some TGSI
shader. However those don't appear to be printed without --enable-debug. I've
pushed out a fix for another assertion, so try a mesa git head build (make sure
it includes commit eca8f38dcffb7), with --enable-debug, and run with
ST_DEBUG=tgsi -- that should hopefully show which shader r600 is having trouble
compiling.