doctest + libghc-lens-dev (and other debian haskell libs I guess, on ghc8/testing) = unhandled ELF relocation(RelA) type 42

[Andreas Reuleaux <rx@a-rx.info>]

very simple testfile FooBar.hs as follows:


--------------------
{-# LANGUAGE TemplateHaskell #-}


module FooBar where

import Control.Lens



data FooBar = 
  Foo
  | Bar 


makeLenses ''FooBar
--------------------


I have libghc-lens-dev, doctest, and libghc-doctest-dev installed


loading the above in ghci works fine

  rx@laptop ~ $ ghci FooBar.hs 
  GHCi, version 8.0.1: http://www.haskell.org/ghc/  :? for help
  Loaded GHCi configuration from /home/rx/cfg/hs/dot-ghci
  [1 of 1] Compiling FooBar           ( FooBar.hs, interpreted )
  Ok, modules loaded: FooBar.
  *FooBar > 


trying to run doctest on FooBar results in

  rx@laptop ~ $ doctest FooBar.hs 
  doctest: /usr/lib/haskell-packages/ghc/lib/x86_64-linux-ghc-8.0.1/lens-4.14-9dVzUyOAXSjIX3UgJ3NnoU/libHSlens-4.14-9dVzUyOAXSjIX3UgJ3NnoU.a: unhandled ELF relocation(RelA) type 42

  doctest: Could not on-demand load symbol 'lenszm4zi14zm9dVzzUyOAXSjIX3UgJ3NnoU_ControlziLensziTH_makeLenses_closure'

  doctest: 
  ByteCodeLink.lookupCE
  During interactive linking, GHCi couldn't find the following symbol:
    lenszm4zi14zm9dVzzUyOAXSjIX3UgJ3NnoU_ControlziLensziTH_makeLenses_closure
  This may be due to you not asking GHCi to load extra object files,
  archives or DLLs needed by your current session.  Restart GHCi, specifying
  the missing library using the -L/path/to/object/dir and -lmissinglibname
  flags, or simply by naming the relevant files on the GHCi command line.
  Alternatively, this link failure might indicate a bug in GHCi.
  If you suspect the latter, please send a bug report to:
    glasgow-haskell-bugs@haskell.org

  rx@laptop ~ $


on ghc 7.10.3 I don't have these problems:

  rx@softland ~ $ doctest --version
  doctest version 0.11.0
  using version 7.10.3 of the GHC API
  using /usr/bin/ghc-7.10.3
  rx@softland ~ $ doctest FooBar.hs 
  Examples: 0  Tried: 0  Errors: 0  Failures: 0
  rx@softland ~ $ 



not sure what is causing these issues, and how to handle them (work around them) properly:

have tried various things, like eg "-opta-Wa,-mrelax-relocations=no"
as suggested in https://github.com/DanielG/ghc-mod/issues/762
with no luck so ar


purging libghc-doctest-dev and instead cabal installing lens from
hackage resulted in other similar relocation(RelA) type 42 problems,
if I remember right, and is just not feasible for my larger projects
(want to rely on debian haskell packages in as much as possible)

Can anyone confirm these issues, has a solution maybe?

Thanks
  Andreas