On the pandas dev call this morning we discussed whether to bump the cython version we are using from 0.29.x to the most recent 3.0 alpha. The main _new_ point that was made was that we should stick to versions that are available on conda-forge. The latest there is 0.29.24. Aside from that, I'll be doing a build locally to see if we _can_ use 3.0a9 and we'll revisit the question at next month's meeting.