| I guess it's the CI/CD infrastructure. Pipeline and time requirement grows exponentially as the code supports more operating systems and configurations. I used a GitLab + GitLab Runner (docker) pipeline for my Ph.D. project which did some verification after every push (since the code was scientific), and even that took 10 minutes to complete even if it was pretty basic. Debian's some packages need more than three hours in their own CI/CD pipeline. Something like Mozilla Firefox, which is tested against regressions, performance, etc. (see https://www.arewefastyet.com) needs serious infrastructure and compute time to build in n different configurations (stable / testing / nightly + all the operating systems it supports) and then test at that scale. This needs essentially a server farm, to complete in reasonable time. An infrastructure of that size needs at least two competent people to keep it connected to all relevant cogs and running at full performance, too. So yes, it's a significant effort. |
Firefox does indeed have a large CI system and ends up running thousands of jobs on each push to main (formerly mozilla-central), covering builds, linting, multiple testsuites, performance testing, etc. all across multiple platforms and configurations. In addition there are "try" pushes for work in progress patches, and various other kinds of non-CI tasks (e.g. fuzzing). That is all run on our taskcluster system and I don't believe there are any plans to change that.