https://github.com/rwjblue/ember-cli-cjs-transform/blob/master/src/cjs-transform.js#L19
Line above assumes username exists, but if for example "ember test" is run with
docker run --user $(id -u):$(id -g) --env XDG_CONFIG_HOME=/myapp/build/.config --env CI=true -i --rm -v $(pwd):/myapp danlynn/ember-cli:latest ember test
Then the docker container is without $HOME and username.
See related issue: sindresorhus/username#21