conda search -c main numba | grep py36 shows that numba 0.36.1 is the oldest package compatible with python 3.6 and numpy 1.12. The numba git history says 0.36.1 was released on Dec 7, 2017. (0.17.0 was released Feb 3, 2015.) I'll add that to the asv conf.

I'd be fine with also adding a minimum numba requirement to setup.py, but I think that should be done in combination with changes to the import logic in spa.py. In particular, I don't like the numpy fallback - that led to hard to track down errors when developing this. It would also be worth reviewing modern numba best practices. If we're adding a minimum numba requirement to setup.py then we should probably be testing against it too. More than I want to tackle in this PR.

Originally posted by @wholmgren in #1059 (comment)