kokoro: update ubuntu to bionic

[acomodi]

Tries to fix #1833

Signed-off-by: Alessandro Comodi acomodi@antmicro.com

[acomodi]

@mithro I am not sure how to really update the ubuntu version used by kokoro. The problem I think is that only Ubuntu versions >= 18.04 have valid python versions from the deadsnakes PPA.

...
Supported Ubuntu and Python Versions
====================================

- Ubuntu 18.04 (bionic) Python2.3 - Python 2.6, Python 3.1 - Python 3.5, Python3.7 - Python3.11
- Ubuntu 20.04 (focal) Python3.5 - Python3.7, Python3.9 - Python3.11
- Note: Python2.7 (all), Python 3.6 (bionic), Python 3.8 (focal) are not provided by deadsnakes as upstream ubuntu provides those packages.
- Note: for focal, older python versions require libssl1.0.x so they are not currently built

The packages may also work on other versions of Ubuntu or Debian, but that is not tested or supported.

For reference: deadsnakes/issues#195

[mithro]

Ubuntu version of the kokoro runner can't be changed (yet another reason to move to GitHub Action Runners). Maybe you can use the same fix at https://github.com/verilog-to-routing/vtr-verilog-to-routing/pull/1964/files or use conda?

GitHub

CI: fix kokoro failures by lpawelcz · Pull Request #1964 · verilog-to-routing/vtr-verilog-to-routing

Signed-off-by: Pawel Czarnecki pczarnecki@antmicro.com

Description

I see that kokoro fails in recent CI runs with:
++ pyenv install -f 3.6.3
Downloading Python-3.6.3.tar.xz...
-> https://www.p...

[umarcor]

@acomodi, since Kokoro is not used anymore, can this PR be closed?

[pgielda]

I remember that there is some procedure to remove Kokoro in the end that has to be done by @mithro externally to the codebase... But maybe this was already done?

[umarcor]

Closing as the pending procedure mentioned by @pgielda is done: #1873.