Hi all, I'm moving some discussion from the comments in issue #1212 over to the mailing list: https://bitbucket.org/yt_analysis/yt/issues/1212 I wanted to check with the list since Cameron objected a bit in the issue discussion. The issue Cameron identifies is pretty serious, but fully fixing it will require pretty substantial work - adding support for octree data to the AMRKDTree. I've gone ahead and marked it for version 3.4 - i.e. that it shouldn't be a blocker for the 3.3 release. I've also created issue 1215: https://bitbucket.org/yt_analysis/yt/issues/1215 which will be fixed when yt produces a useful error message rather than seg faulting when trying to construct an AMRKDTree for unsupported data. I think that requiring someone to add support for octree data to the AMRKDTree before we release 3.3 is effectively delaying the 3.3 release arbitrarily far into the future, since no one is currently willing to work on that project. That would be unfortunate, because there's lots of cool stuff people have worked on that deserves a stable release. -Nathan