That’s true, you can see that sscce which shows that a 5s delay is present when you remove your elm-stuff/ and the compiler then tries to update its list of packages.
It turns out there is a rather simple trick to get rid of that 5s delay. The library used for http in the elm compiler can pick up a proxy set in the https_proxy environment variable. So I found a simple config for tinyproxy that fail all requests and effectively removes the 5s delay observed. Here is the config and how I use it in a docker container to run tests: elm-test-runner/bin/run.sh at 51df0350f0e74bd6cc8e7ecaf49e8c0ae6f81212 · exercism/elm-test-runner · GitHub