The problem was a strange monorepo setup where multiple packages came from the same GitHub repo. Then I tried to switch one of them to my fork. The error messag

The problem was a strange monorepo setup where multiple packages came from the same GitHub repo. Then I tried to switch one of them to my fork. The error message did not help me understand this reality at all; I only figured it out the very hard way after blowing up my project in two different ways.