[Haskell-cafe] Fails to `stack exec` a Yesod app

Hi, I have the following project (https://github.com/yohad/TheMafsidan). 'stack build` works with no errors but when I try to run it I get App: static: getDirectoryContents:openDirStream: does not exist (No such file or directory) Anyone has a clue on how to fix this? Yotam