Updating fastboot to 2.x broke ember-cli-fastboot when using ember-fetch.
Interestingly enough, this is apparently the same issue there was with fastboot-app-server with fastboot 1.x, fixed by upgrading to 2.x. (#686)
But in ember-cli-fastboot this happens with fastboot 2.x and doesn't with fastboot 1.x (ember-cli/ember-fetch/issues/184) 🤔