`executable-dynamic: True` should apply to `build-type: Custom` setup

[accursoft]

I have a Haskell installation with only shared libraries, and cabal's config contains:

library-vanilla: False
library-profiling: False
shared: True
executable-dynamic: True

This fails for packages with build-type: Custom, because cabal-install tries to link setup against non-existent static libraries.

[Piezoid]

I use -dynamic in ghc-options as a workaround (with a similar configuration). But yes it need to be fixed.

This workaround is problematic if you build static libraries in a sandbox (for example profiling libraries) , the ghc-options are propagated and can't be cleared.

[int-e]

Perhaps there should be an extra option like ghc-options just for building Setup executables. Note that this is related to cross-compilation as well: once it's possible to specify a host compiler (cf. #1493) it seems natural to have a way of specifying additional flags for it as well.

[int-e]

There is another facet of this issue: If ghc is built without static (aka vanilla) libraries, then even the default Setup executables for the Simple build type fail to build.

[Rufflewind]

FWIW this does affect Arch Linux now, because the default packages don't come with static libs anymore.

[nponeccop]

JFYI alex is one of the widely known packages with custom-setup and without too many deps. It fails during configure step:

[foo@arch alex-test]$ cabal install alex
Resolving dependencies...
Notice: installing into a sandbox located at
/home/foo/dev/alex-test/.cabal-sandbox
Configuring alex-3.2.3...
Failed to install alex-3.2.3
Build log ( /home/foo/dev/alex-test/.cabal-sandbox/logs/alex-3.2.3.log ):
cabal: Entering directory '/tmp/cabal-tmp-21549/alex-3.2.3'
cabal: Leaving directory '/tmp/cabal-tmp-21549/alex-3.2.3'
cabal: Error: some packages failed to install:
alex-3.2.3 failed during the configure step. The exception was:
user error ('/usr/bin/ghc' exited with an error:
/usr/bin/ld: cannot find -lHSCabal-1.24.2.0
/usr/bin/ld: cannot find -lHSprocess-1.4.3.0
/usr/bin/ld: cannot find -lHSpretty-1.1.3.3
/usr/bin/ld: cannot find -lHSdirectory-1.3.0.0
/usr/bin/ld: cannot find -lHSunix-2.7.2.1
/usr/bin/ld: cannot find -lHStime-1.6.0.1
/usr/bin/ld: cannot find -lHSfilepath-1.4.1.1
/usr/bin/ld: cannot find -lHSbinary-0.8.3.0
/usr/bin/ld: cannot find -lHScontainers-0.5.7.1
/usr/bin/ld: cannot find -lHSbytestring-0.10.8.1
/usr/bin/ld: cannot find -lHSdeepseq-1.4.2.0
/usr/bin/ld: cannot find -lHSarray-0.5.1.1
/usr/bin/ld: cannot find -lHSbase-4.9.1.0
/usr/bin/ld: cannot find -lHSinteger-gmp-1.0.0.1
/usr/bin/ld: cannot find -lHSghc-prim-0.5.0.0
/usr/bin/ld: cannot find -lHSrts_thr
collect2: error: ld returned 1 exit status
`gcc' failed in phase `Linker'. (Exit code: 1)
)

A more self-contained example fails with a different error, and it should also fail with "normal" GHC if vanilla is disabled:

Setup.hs

import Distribution.Simple
import Acme.Missiles
main = defaultMain

foo.cabal:

name:                foo
version:             0.1.0.0
synopsis: foo
description: bar
homepage:            https://github.com/githubuser/foo#readme
license:             BSD3
license-file:        LICENSE
author:              Author name here
maintainer:          example@example.com
copyright:           2017 Author name here
category:            Web
build-type:          Custom
extra-source-files:  README.md
cabal-version:       >=1.24

custom-setup
  setup-depends: base <5, Cabal <2, acme-missiles <1

executable foo-exe
  hs-source-dirs:      app
  main-is:             Main.hs
  build-depends:       base <5
  default-language:    Haskell2010

The error is:

$ cabal sandbox init
Writing a default package environment file to
/home/foo/dev/alex-test/foo/cabal.sandbox.config
Creating a new sandbox at /home/foo/dev/alex-test/foo/.cabal-sandbox
$ cabal install
Resolving dependencies...
Notice: installing into a sandbox located at
/home/foo/dev/alex-test/foo/.cabal-sandbox
Configuring acme-missiles-0.3...
Building acme-missiles-0.3...
Installed acme-missiles-0.3
Configuring foo-0.1.0.0...
Failed to install foo-0.1.0.0
Build log ( /home/foo/dev/alex-test/foo/.cabal-sandbox/logs/foo-0.1.0.0.log ):
cabal: Entering directory '.'
cabal: Leaving directory '.'
cabal: Error: some packages failed to install:
foo-0.1.0.0 failed during the configure step. The exception was:
user error ('/usr/bin/ghc' exited with an error:

dist/dist-sandbox-aeee24c4/setup/setup.hs:2:1: error:
Failed to load interface for ‘Acme.Missiles’
There are files missing in the ‘acme-missiles-0.3’ package,
try running 'ghc-pkg check'.
Use -v to see a list of the files searched for.
)

[LeifW]

Just to expand on @Piezoid's comment, using cabal install --ghc-option=-dynamic foo, or adding ghc-options: -dynamic in my $HOME/.cabal/config works for me as a workaround.