scripts/ubuntu-req.sh not configured for Ubuntu 20.04

[brendonsb]

The Ubuntu requirements script specifies the apt package, python3.6. This package is not available in the current 20.04 repos casuing the script to fail at that point.

[hngenc]

I think this is an issue with Chipyard rather than with Gemmini. scripts/ubuntu-req.sh is outside the scope of our project.

[hngenc]

Oops, sorry, I was on the wrong project page :). Re-opening this

[alonamid]

Python 3.6 is the minimum requirement, not a "sole" requirement. Ubuntu 20.04 includes python 3.8, which should satisfy the requirement without need to pull a special package (unlike Ubuntu 16.04 which is the earliest Ubuntu we support).

I agree that the scripts/ubuntu-req.sh script is not robust to multiple Ubuntu versions. We will happily accept a PR to make it more robust.

[abejgonzalez]

There is a current PR trying to see if the change is backwards compatible: #869

[abejgonzalez]

I think this is solved with #874. Closing for now. Feel free to re-open if there are still issues.