If there's no stack.yaml it uses the global ~/.stack/global/stack.yaml.
So you should be able to open any random file and it'll work out. E.g. if I open ~/X.hs and import Lucid, I can just run stack build lucid in my ~/ and now M-x intero-restart and it has access to that package.
So you should be able to open any random file and it'll work out. E.g. if I open ~/X.hs and import Lucid, I can just run stack build lucid in my ~/ and now M-x intero-restart and it has access to that package.