Cabal#9784 minimized repro case

README.md

Issue haskell/cabal#9784

Found & minimized on Linux. In CI, reproduces on Windows too, see issue.

Steps to reproduce

1. Download or git-clone this gist
2. Set executable-dynamic: True in ~/.cabal/config
   • ⚠️ important: don't pass as a flag --enable-executable-dynamic, set in the config.
     The flag has different effect (specifically: no effect) from the config option. That's the bug.
3. cabal v2-install

Expected result

Installs, successfully running the executable from postCopy Setup hook, that prints Module Main speaking.

Actual result

dist/build/cabal9784-repro/cabal9784-repro: error while loading shared libraries: libHScabal9784-repro-0.1-273208628f9b290e48d0007c2a55aff138469cc5ac0dd78b416c2ef6e98387a2-ghc9.6.4.so: cannot open shared object file: No such file or directory

cabal9784-repro.cabal

cabal-version:      2.0
name:               cabal9784-repro
version:            0.1
synopsis: Minimal bug repro case
homepage: https://github.com/haskell/cabal/issues/9784
license:            PublicDomain
author:             Max Ulidtko
maintainer:         ulidtko@gmail.com

build-type:         Custom

custom-setup
  setup-depends:
    base     >= 4.12.0.0 && < 4.20,
    Cabal    >= 2.4.0.1  && < 3.11,
    filepath >= 1.4.2.1  && < 1.5,
    process  >= 1.6.3.0  && < 1.7

library
  hs-source-dirs:   .
  build-depends:    base ^>=4.18.2.0
  default-language: Haskell2010
  exposed-modules:  LibModule

executable cabal9784-repro
  hs-source-dirs:   .
  main-is:          Main.hs
  default-language: Haskell2010
  build-depends:    base ^>=4.18.2.0, cabal9784-repro

LibModule.hs

module LibModule where

greeting = "=== Hello, Cabal! === Module Main speaking ~~~"

Main.hs

module Main where

import LibModule

main :: IO ()
main = putStrLn LibModule.greeting

Setup.hs

import Distribution.Simple
import Distribution.Simple.BuildPaths (exeExtension)
import Distribution.Simple.LocalBuildInfo (LocalBuildInfo, buildDir)
import Distribution.PackageDescription (PackageDescription)
import Distribution.Simple.Setup
import Distribution.System (buildPlatform)
import Distribution.Types.HookedBuildInfo

import System.FilePath ((</>), (<.>))
import System.Process (callCommand, callProcess)

main = defaultMainWithHooks simpleUserHooks
  { postBuild = postBuild'
  , preCopy   = preCopy'
  , postCopy  = postCopy'
  }

postBuild' :: Args -> BuildFlags -> PackageDescription -> LocalBuildInfo -> IO ()
postBuild' _ flags pd lbi = do
  putStrLn "=== Hello, Cabal! === Setup's postBuild hook speaking ~~~"

preCopy' :: Args -> CopyFlags -> IO HookedBuildInfo
preCopy' args flags = do
  putStrLn "=== Hello, Cabal! === Setup's preCopy hook speaking ~~~"
  return emptyHookedBuildInfo

postCopy' :: Args -> CopyFlags -> PackageDescription -> LocalBuildInfo -> IO ()
postCopy' _ flags pd lbi = do
  putStrLn "=== Hello, Cabal! === Setup's postCopy hook speaking ~~~"
  -- callCommand "set -x; pwd && ls -lh"
  let exe = buildDir lbi </> "cabal9784-repro"
                         </> "cabal9784-repro" <.> exeExtension buildPlatform
  callProcess exe []