sage-native-execute python is finding you system python. It seems that somehow Sage's python doesn't work? Can you execute /home/ubuntu/sage/local/bin/python? (notice your question had a typo in the path---is that a typo or was that the real error message?)
sage-native-execute python is finding you your system python. It seems that somehow Sage's python doesn't work? Can you execute /home/ubuntu/sage/local/bin/python? (notice your question had a typo in the path---is that a typo or was that the real error message?)