Hi, It looks like you've added `text` to the list of dependencies for the executable, rather than the library. Try adding it to the `build-depends` field of the library block in the cabal file instead. Cheers, David On 28 May 2017 07:41, "Dennis Raddle" wrote:

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.

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Without seeing all the files I'd guess you added the `text` package under the `build-depends` of the executable, and not of the library. Is that correct? On Sun, May 28, 2017 at 8:41 AM, Dennis Raddle wrote:

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.

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