Wanted to follow up and see if anyone had any thoughts about this. To summarize: attempting to generate chagnesets >= 1.0 GB and < 2.0 GB fails with OOM. I believe this is the incorrect behavior caused by an issue with sessionBufferGrow. Patch included here: https://gist.github.com/R4N/fe4f0696bbb835cd5796e46f99328647