OSX 10.10.2, GTX970
Short description of error
This is a bit of a weird bug.
Blender hangs when combining the soften node and the dilate erode node together with masking. It only happens if soften and dilate are active, if one of them is muted blender works fine. I suspect the dilate/erode node is problematic in some way anyway, because if i set it to linear feathering, i get these issues in the console: http://www.pasteall.org/58689
I guess the interesting line here is "BLI_assert failed: /Volumes/blender/source/blender/compositor/operations/COM_BlurBaseOperation.cpp:144, make_dist_fac_inverse(), at '0'"
Exact steps for others to reproduce the error
Open this file:
Tweak the mask rapidly, maybe by moving its center point quickly in small steps around. At some point blender just hangs and has to be killed. No errors in the console, not even with --debug or even using lldp. It's superweird. And: i couldn't reproduce on linux.