Failed with integer-gmp about ghc-musl

[utdemir]

Thanks @nodew.

So, the error you are getting is expected (does not mean that it is not annoying): A few dependencies (hashable, cryptonite) of haskell-realworld-example pull in integer-gmp, which is not supported by this project. This is by design, as libgmp has licensing restrictions when linked statically.

However, this is not a big issue:

• Before GHC 9, GHC supports two integer implementations integer-gmp and integer-simple. Usually, libraries which depend on integer-gmp has flags to make them depend on integer-simple instead. eg: hashable.cabal
• After GHC 9, GHC comes with a single library called ghc-bignum, which has two implementations (gmp-backend and native-backend). So the libraries can depend on ghc-bignum unconditionally and it should just work.

So, there are two solutions that can get you past the issue:

1. Keep using 8.x, and figure out how to get your dependencies use integer-simple instead. It should be an exercise of figuring out the correct flags to pass (on cabal.project or stack.yml).
2. Use a GHC version newer than 9.0. Then, the dependencies would use ghc-bignum which should work without any headaches.

---

Unfortunately, even after the above changes haskell-realworld-example does not build, as it depends on libpq which has problems with static linking. We already have an issue for that: #15

Let me know if you can get past the gmp issue (or happy with the explanation), then I suggest we close this issue. If you also get the libpq error, feel free to pitch in to #15; or create another issue if you get another error.

Thanks again for the issue.

[utdemir]

That is interesting. The images usually use integer-simple, so I think it might not be possible to build things that depend on integer-gmp specifically.

Can you share your code, and if that's not public, the build-dependencies field of your .cabal file?

[nodew]

That is interesting. The images usually use integer-simple, so I think it might not be possible to build things that depend on integer-gmp specifically.

Can you share your code, and if that's not public, the build-dependencies field of your .cabal file?

@utdemir Sure, it's an open source project haskell-realworld-example