ci: explain some circle decisions
@@ -371,7 +371,12 @@ jobs:
#
# To modify the contents of the CI image, update docker/Dockerfile.ci
ci_image:
+ # Use a `machine` executor instead of a docker-based because:
+ # - we bootstrap our CI images somehow (we could use a docker-hub image as well)
+ # - the machine executor also supports multi-arch builds
+ # - we only run this job once a day, so the additional startup delay of 30-60s doesn't really matter
machine:
+ # https://circleci.com/docs/2.0/configuration-reference/#available-machine-images
image: ubuntu-2004:202107-02
resource_class: xlarge
steps:
