language server working directory is "arbitrary"

It probably is a bug in haskell-language-server, but it requires the working directory to be the project directory.

Even though the "Startup behavior" is "Start Server per Project", the working directory is not changed from the default (where Qt Creator was started from the Terminal, or probably ~/ if started through "open", Dock, or Finder on macOS).

haskell-language-server has a "--cwd" option, but there is no sensible variable to set that to (%{ActiveProject:....} is wrong, as is %{CurrentDocument:Project:....}). It would probably generally make sense to have access to the "project" specific macro expander.