I’m getting the following error at build time:

[13 of 21] Compiling Actions          ( /home/gallaecio/proxectos/paquetes/repositorios/games/hedgewars/src/hedgewars-src-0.9.18/gameServer/Actions.hs, /home/gallaecio/proxectos/paquetes/repositorios/games/hedgewars/src/hedgewars-src-0.9.18/build/gameServer/Actions.o )
[ 49%] 
/home/gallaecio/proxectos/paquetes/repositorios/games/hedgewars/src/hedgewars-src-0.9.18/gameServer/Actions.hs:86:10:
    Duplicate instance declarations:
      instance NFData B.ByteString
        -- Defined at /home/gallaecio/proxectos/paquetes/repositorios/games/hedgewars/src/hedgewars-src-0.9.18/gameServer/Actions.hs:86:10
      instance NFData B.ByteString
        -- Defined in `Data.ByteString.Internal'
Building CXX object QTfrontend/CMakeFiles/hedgewars.dir/ui/widget/igbox.cpp.o
make[2]: *** [bin/hedgewars-server] Erro 1
make[1]: *** [gameServer/CMakeFiles/hedgewars-server.dir/all] Erro 2
make[1]: *** Agardando por traballos non rematados....

I’m using 7.6.1 and bytestring-show 0.3.5.4.

Any idea about why this is happening or how can I solve it?