I'm happy to report I'm now looking at a cool sage:
prompt. Since the last error message also alluded to cython > ImportError: > /usr/lib/python3/dist-packages/sage/libs/gap/element.cpython-37m-i386-linux-gnu.so: > undefined symbol: GAP_EnterStack_ I tried manually upgrading the cython3 package from 0.29.2-2 to 0.29.14-0.1+b1. I wish I were more confident I knew what actually fixed it, but as a practical metter, it's OK with me if you close this bug report. So, Kingsley -- Time is the fire in which we all burn.