Trying to learn stack. I'm following the tutorial on this page:

https://docs.haskellstack.org/en/stable/GUIDE/

I built helloworld. Then I modified Lib.hs to include Data.Text.IO, as the tutorial specifies. I typed 'stack build' and got the error that the text package wasn't installed, as the tutorial says I would. I then modified helloworld.cabal to have these lines:

build-depends: base

, helloworld

, text

and typed 'stack build' again. I got the exact same output - an error on building Lib.hs, 'Failed to load interface for Data.Text.IO. I checked that I really modified al lthe right files and can't find anything I did wrong.