spelling mistake `source_dirs` is not flagged as error and produces incorrect cabal file

[andrewufrank]

I have a stack.yaml with two executable and the cabal file does not include the hs-course-dirs for the second executable. The problem was that I misspelled source_dirs (underbar in stead of dash). It would be nice if hpack would flag such hard to track errors...

Would it be possible, to include common parts for all executables in front of the list of executables, like so:

executables:
    source-dirs:         app
    ghc-options:
    - -threaded
    - -rtsopts
    - -with-rtsopts=-N
    - -Wno-deprecations
  primo-exe:
    main:                Main.hs
    dependencies:
    - primo
  fixmd:
    main:               fixmd.hs

(-- This file has been generated from package.yaml by hpack version 0.33.0.
--
-- see: https://github.com/sol/hpack
--
-- hash: 96ef3f0dac1ff9a02d9d4c24823b8f5dff5585876922f4ad4a66da5895193196)