Admin message

Due to a large amount of spam we do not allow new users to create repositories, they are "external" users. If you are a new user and want to create a repository, for example for forking GHC, open a new issue on ghc/ghc using the "get-verified" issue template

UnitIndexCache is reinitialising with multiple home units
In `initMulti` we call `initUnitEnv` after using the `hscUIC` to initialise the external units in `initUnits`. This leads to the UnitIndex to be empty after calling `initMulti` which violates the property that all UnitInfos must be present in the `UnitIndexCache`.
issue