ghc-mod not properly detecting project

[cocreature]

Sending

{"cmd":"ghcmod:type","params":{"file":{"file":"/home/moritz/code/haskell/haskell-ide-engine/hie-base/Haskell/Ide/Engine/PluginTypes.hs"},"start_pos":{"line":302,"col":8},"end_pos":{"line":302,"col":8}}}``
to `hie` where `hie` is a binary at `~/.local/bin/hie` results in

EXCEPTION: types:
Could not find module ‘Data.Aeson’
Perhaps you meant Data.Version (from base-4.8.2.0)
Use -v to see a list of the files searched for.
Could not find module ‘Data.Aeson.Types’
Use -v to see a list of the files searched for.
Could not find module ‘Data.HashMap.Strict’
Perhaps you meant
Data.IntMap.Strict (from containers-0.5.6.2)
Data.Map.Strict (from containers-0.5.6.2)
Use -v to see a list of the files searched for.
Could not find module ‘Data.Singletons.Prelude’
Use -v to see a list of the files searched for.
Could not find module ‘Data.Text’
Perhaps you meant Data.Set (from containers-0.5.6.2)
Use -v to see a list of the files searched for.
Could not find module ‘Data.Vinyl’
Use -v to see a list of the files searched for.
Could not find module ‘Data.Singletons.TH’
Use -v to see a list of the files searched for.
{"type_info":[]}

When using `stack exec hie` it works fine. Also the `ide-backend` plugin works correctly and since that gets the package dbs from ghc-mod I don’t think it’s a bug in ghc-mod itself, but we’re just using it wrong.

Most likely #161 will fix this (I’ll try to work on that during the weekend) but for the meantime I want to record this bug here.