単に
$ pip3 install numba -U
だけでインストールできるようになっていた.
Collecting numba Downloading numba-0.35.0-cp36-cp36m-macosx_10_7_x86_64.whl (1.4MB) 100% |████████████████████████████████| 1.4MB 264kB/s Requirement already up-to-date: numpy in /usr/local/lib/python3.6/site-packages (from numba) Collecting llvmlite (from numba) Downloading llvmlite-0.20.0-cp36-cp36m-macosx_10_7_x86_64.whl (11.0MB) 100% |████████████████████████████████| 11.0MB 101kB/s Installing collected packages: llvmlite, numba Found existing installation: llvmlite 0.18.0 Uninstalling llvmlite-0.18.0: Successfully uninstalled llvmlite-0.18.0 Found existing installation: numba 0.33.0 Uninstalling numba-0.33.0: Successfully uninstalled numba-0.33.0 Successfully installed llvmlite-0.20.0 numba-0.35.0