- operating-system: ['ubuntu-latest'] # @todo add 'windows-latest'
- # @todo use an older version of phpunit to enable testing on php 5.3 - 5.5
+ # @see https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners
+ # @todo fix: atm our tests fail when using ubuntu 20 (focal) and php 5.6 - 7.1, when using
+ # an ssl stream context for connecting to localhost via https
+ operating-system: ['ubuntu-18.04'] # @todo add 'windows-latest'
+ # @todo use an older version of phpunit to enable testing on php 5.3 - 5.5 . Also: we will most likely
+ # have to resort to using shivammathur/setup-php@v2 instead of sury's ppa to get php installed