The project contains no local packages (packages not marked with 'extra-dep')

[mhwombat]

Following the instructions in the README; stack build fails.

$ git clone --recursive https://github.com/ucsd-progsys/liquidhaskell-tutorial.git
Cloning into 'liquidhaskell-tutorial'...
remote: Enumerating objects: 1911, done.
remote: Total 1911 (delta 0), reused 0 (delta 0), pack-reused 1911
. . .
$ cd liquidhaskell-tutorial/
$ stack install
Error parsing targets: The project contains no local packages (packages not marked with 'extra-dep')

Stack used to allow you to have a stack.yaml where all of the packages were external, but it no longer does. One possible workaround is to have a trivial local package ("Hello, Liquid Haskell").