doctests stuck on big-endian 64-bit architectures

Summary

We noticed that with ghc-8.6.5, doctests are failing (stuck for ever) on big-endian 64-bit architectures.

Steps to reproduce

$ cabal get distributive
$ cd distributive-0.6.1
$ cabal install --enable-tests

$ ghci
>>> import Data.Distributive
>>> distribute [(+1),(+2)] 1
[2,3]

which runs successfully, but if I try to load the package from the build directory:

$ ghci -i \
-i.../distributive-0.6.1/dist/build/autogen \
-i.../distributive-0.6.1/dist/build \
-i.../distributive-0.6.1/src \
-hide-all-packages \
-package-db=dist/package.conf.inplace \
-optP-include \
-optPdist/build/autogen/cabal_macros.h \
-package-id=base-4.12.0.0 \
-package-id=base-orphans-0.8.1-HeyTAcy4PKhDcGhjvJwDzq \
-package-id=tagged-0.8.6-AoE7RQX12AwJxLvAxGYxtP \
-package-id=transformers-0.5.6.2 \
-package=distributive-0.6.1 \
Data.Distributive
>>> distribute [(+1),(+2)] 1

it gets stuck. I believe the above is the reason why doctests are not completing.

Environment

• GHC version used: v8.6.5

This used to work with ghc-8.4.4.