Hakyll is a static site generator library in Haskell. More information (including a tutorial) can be found on the hakyll homepage.
You can install this library using cabal:
cabal install hakyll
Or using stack:
stack install hakyll
If Stack fails, please see which Stackage snapshots contain
Hakyll and specify one
explicitly, e.g. stack install --resolver=lts-19.0 hakyll.