I'm just pinging #python-dev to see if there's a way to request a buildbot build from a specific server-side clone.
Meanwhile, though, I definitely introduced a change into your code which I thought I had reverted, but clearly hadn't! The code, as committed, used PyMem_RawAlloc in place of the calloc() call you had, but didn't replace the later free() by its PyMem counterpart.
If I don't get any joy with the clone-specific buildbot question, I'll just rebuild from your original patch, re-commit, and watch the buildbots.