Build chain bug: pynrm.so needs -lHSrts-ghc8.6.5
This used to be injected at shell time in cabal files. we need a more robust/standard way to add
extra-lib-dirs. On current master this breaks
- add library location dynamically at build time without relying on nix path
- add a CI test for pynrm.so, which now fails with an unresolved symbol error.