Why stop at ~~"stable"~~ `jessie`? Having versions for the ~~"testing"~~ `ascii` and ~~"unstable"~~ `ceres` suites might be useful for some. It should be mostly a matter of adding (parallelized!) build snippets to `.gitlab-ci.yml`. There may be a few kinks due to changes of course and these should be ironed out in such a way that *all three* suites build without failure. This should at least cover the base `devuan` image but having `devuan/builder` (and `devuan/helper`?, see #1) images for ~~"unstable"~~ `ceres` would be beneficial for packaging efforts. Having such images for ~~"testing"~~ `ascii` is likely not all that useful as packages normally enter via ~~"unstable"~~ `ceres`. Of course, "slim" variants (#2) would be nice too.