Hi Nathan, Yes, that of course was it. (I wonder how many times I’ll have this error before I can remember that’s the solution as a matter of course…..) Thanks, —Molly On October 5, 2016 at 12:14:41 PM, Nathan Goldbaum (nathan12343@gmail.com<mailto:nathan12343@gmail.com>) wrote: Hi Molly, Did you do "python setup.py develop" in the root of the repository after pulling from the main yt repo? The `cosmology_time` module is a recently added bit of cython code, which needs to be compiled. -Nathan On Wed, Oct 5, 2016 at 11:12 AM, Molly Peeples <molly@stsci.edu<mailto:molly@stsci.edu>> wrote: Hi folks, I just updated yt and now I’m getting this: http://pastebin.com/FGGDBTKU I believe I’m on the tip of the dev branch. Ideas? —Molly _______________________________________________ yt-dev mailing list yt-dev@lists.spacepope.org<mailto:yt-dev@lists.spacepope.org> http://lists.spacepope.org/listinfo.cgi/yt-dev-spacepope.org _______________________________________________ yt-dev mailing list yt-dev@lists.spacepope.org http://lists.spacepope.org/listinfo.cgi/yt-dev-spacepope.org