> Docker takes about 10m to build: https://jenkins.dockerproject.org/job/docker/job/docker.gith....

That seems to be docker.github.io, the Docker documentation, not Docker itself (and not written in Go).

Go's main compilation performance gains come from incremental compilation. Since C++ doesn't have real module support merely parsing the entire dependency graph from headers can take a very long time. In go if you have .a pkgs for all your dependencies your program will compile very fast.

If you use docker as part of your ci build the dependencies as a separate step so they can be cached between builds. This is especially important for libraries like sqlite, which can take a lot longer to compile.

On a not-too-old notebook, building k8s needs less than one minute.