CI select default Ubuntu version

Many CI services use Ubuntu for their default Linux distro. The default Linux / Ubuntu version is typically an older version. It can be convenient to switch CI jobs to a newer Linux version to get more recent libraries. Here are examples of switching Linux version for a few popular CI services.

GitHub Actions

GitHub Actions default Ubuntu version is controlled with .github/workflows/*.yml file(s). For example, Ubuntu 20.04 may be selected with

jobs:

  linux:
    runs-on: ubuntu-20.04

Travis-CI

Travis-CI default Ubuntu version is controlled in .travis.yml. For example, Ubuntu 20.04 may be selected in .travis.yml with

dist: focal

AppVeyor

AppVeyor default Ubuntu version is controlled in .appveyor.yml. For example, Ubuntu 20.04 may be selected in .appveyor.yml with

image: Ubuntu2004