by Chris Cave-Ayland
In the Imperial RSE Team we make extensive use of continuous integration (CI) with
GitHub Actions. We use CI to ensure our projects build and are correct across a range of
scenarios (OS, python version, dependency version, etc.). Widely accepted wisdom is that
it is best practice to catch issues early via frequent and thorough CI rather than to
catch them later. This must however be set against the monetary and environment cost of
running unnecessary compute workloads on every push to GitHub. In particular, the
pricing structure of GitHub Actions means workloads run on Windows and MacOS are more
costly (certainly financially and presumably environmentally). This is particularly the
case for private repositories for which Imperial has a fixed budget of minutes.