Citing from http://hydra.cryp.to/build/1533084/log/raw: Configuring ghcjs-0.2.0... Setup: At least the following dependencies are missing: aeson >=0.7 && <0.10, haskell-src-exts ==1.16.*, optparse-applicative ==0.11.*, syb >=0.4 && <0.6 This issue has been present for a while now, and it's only gotten worse.