stack setup fails with libgmp in non-standard location

[Stephan Schiffels]

Hi, I am trying to install a package and so far fail in the "stack setup" step. Here is the error:

$ stack setup

The GHC located at /home/ss839/.stack/programs/x86_64-linux/ghc-gmp4-8.0.1/bin/ghc failed to compile a sanity check. Please see:

    http://docs.haskellstack.org/en/stable/install_and_upgrade/

for more information. Exception was:

Running /home/ss839/.stack/programs/x86_64-linux/ghc-gmp4-8.0.1/bin/ghc /tmp/stack-sanity-check30968/Main.hs -no-user-package-db in directory /tmp/stack-sanity-check30968/ exited with ExitFailure 1

[1 of 1] Compiling Main             ( /tmp/stack-sanity-check30968/Main.hs, /tmp/stack-sanity-check30968/Main.o )

Linking /tmp/stack-sanity-check30968/Main ...

/usr/bin/ld: cannot find -lgmp

collect2: ld returned 1 exit status

`gcc' failed in phase `Linker'. (Exit code: 1)

The problem is that libgmp is in a non-standard location: /opt/gmp-6.1.1/lib. I know how I can point "stack build" to that location, using --extra-lib-dirs. But there doesn't seem to be such an option for stack setup, is there?

Any help is much appreciated, thanks!

Stephan