This hurts a _lot_ for go builds inside docker containers. There's a ton of custom code in the build jobs I work on to try and copy around go module cache into the container which is quite slow to try and cache as much as possible as re-cloning all the dependencies is very expensive. It does look like there are some solid open source implementations of the go module cache server nowadays (ex. https://docs.gomods.io/). don't see an easy way to run that myself though in parallel to running docker container builds + non-docker container builds so that things can be fast as much as possible.