build and build output

λ kayvan [workspace-haskell/monday-morning/MyFirstProject] → hpack && stack build | pbcopy
generated MyFirstProject.cabal
Stack has not been tested with GHC versions above 8.6, and using 8.8.2, this may fail
Stack has not been tested with Cabal versions above 2.4, but version 3.0.1.0 was found, this may fail
MyFirstProject> configure (lib + exe)
Configuring MyFirstProject-0.1.0.0...
MyFirstProject> build (lib + exe)
Preprocessing library for MyFirstProject-0.1.0.0..
Building library for MyFirstProject-0.1.0.0..
Preprocessing executable 'new-exec' for MyFirstProject-0.1.0.0..
Building executable 'new-exec' for MyFirstProject-0.1.0.0..
Warning: Enabling workaround for Main module 'Main' listed in 'other-modules'
illegally!
Preprocessing executable 'MyFirstProject-exe' for MyFirstProject-0.1.0.0..
Building executable 'MyFirstProject-exe' for MyFirstProject-0.1.0.0..

/home/kayvan/dev/workspaces/workspace-haskell/monday-morning/MyFirstProject/app/NewExec.hs:1:8: error:
    File name does not match module name:
    Saw: ‘Main’
    Expected: ‘NewExec’
  |
1 | module Main where
  |        ^^^^

--  While building package MyFirstProject-0.1.0.0 using:
      /home/kayvan/.stack/setup-exe-cache/x86_64-linux-tinfo6/Cabal-simple_mPHDZzAJ_3.0.1.0_ghc-8.8.2 --builddir=.stack-work/dist/x86_64-linux-tinfo6/Cabal-3.0.1.0 build lib:MyFirstProject exe:MyFirstProject-exe exe:new-exec --ghc-options ""
    Process exited with code: ExitFailure 1

NewExec.hs

module Main where

import Split.LibSplit

main :: IO()
main = do
  input <- getLine
  let result = ourSplit input
  print result
---------------------------

package.yaml

name:                MyFirstProject
version:             0.1.0.0
github:              "githubuser/MyFirstProject"
license:             BSD3
author:              "Author name here"
maintainer:          "[email protected]"
copyright:           "2020 Author name here"

extra-source-files:
- README.md
- ChangeLog.md

# Metadata used when publishing your package
# synopsis:            Short description of your package
# category:            Web

# To avoid duplicated efforts in documentation and dealing with the
# complications of embedding Haddock markup inside cabal files, it is
# common to point users to the README.md file.
description:         Please see the README on GitHub at <https://github.com/githubuser/MyFirstProject#readme>

dependencies:
- base >= 4.7 && < 5

library:
  source-dirs: src
  exposed-modules:
  - Lib
  - Split.LibSplit

  dependencies:
  - split

executables:
  MyFirstProject-exe:
    main:                Main.hs
    source-dirs:         app/
    ghc-options:
    - -threaded
    - -rtsopts
    - -with-rtsopts=-N
    dependencies:
    - MyFirstProject

  new-exec:
    source-dirs: app/
    main: NewExec.hs
    dependencies:
    - MyFirstProject

tests:
  MyFirstProject-test:
    main:                Spec.hs
    source-dirs:         test
    ghc-options:
    - -threaded
    - -rtsopts
    - -with-rtsopts=-N
    dependencies:
    - MyFirstProject