Linking error while trying to build a haskell.nix project

[MangoIV]

When I build plutus-contract everything works fine but as soon as I'm trying to use it in another project I'm getting
<command line>: /nix/store/i3qmxk5w0nkxl3gab75lhzf57c2pq9hx-plutus-contract-lib-plutus-contract-1.0.0.0/lib/x86_64-linux-ghc-8.10.7/libHSplutus-contract-1.0.0.0-1AL5S92CBMQKDifUePrV6X-ghc8.10.7.so: undefined symbol: plutuszmcontractzm1zi0zi0zi0zm1AL5S92CBMQKDifUePrV6X_WalletziEffects_getClientParams1_closure

It's important to note that the function that's undefined is generate by template haskell, because there seem to be a bunch of related issues:
https://gitlab.haskell.org/ghc/ghc/-/issues/21423
haskell/cabal#8114
https://gitlab.haskell.org/ghc/ghc/-/issues/3799
The latter one looks exactly like my problem although it seems to be fixed for 10 years now.

Is is possible, that plutus-contractgets build with a different ghc that I get in my shell/ as soon as I try to build my library with nix?

I've tried running nix develop with --ignore-environment, building with nix build instead of cabal and all the other stuff you would normally try if you're desperate. I'm mainly looking for an idea of a starting point for how to debug this.

Thanks in advance.

[ocharles]

https://raw.githubusercontent.com/MangoIV/plutus-contract/mangoiv/next-node/rip-out-plutus-contract-api/plutus-contract/plutus-contract.cabal doesn't mention Wallet.Effects in exposed-modules or other-modules. I suggest turning on -Wmissing-home-modules, there should have been a warning from the build of plutus-contract (this doesn't look like a Haskell.nix problem).

[MangoIV]

Thank you; how ignorant of me

[ocharles]

@MangoIV Don't worry - happens to all of us! I've seen that error enough times I'm laser focused on it by now 😄

[MangoIV]

The worst thing is when you're debugging Haskell.nix stuff for 7 days straight; at some point you don't even think of such trivial things.
Thank you for your help :)

[L-as]

Maybe -Werror=-Wmissing-home-modules could be enabled in haskell.nix by default?

[ocharles]

I think that is too opinionated and the status quo is correct.

[L-as]

But almost all cases where the warning fires, the build would fail, no?

[L-as]

You could enable it just for the main project.

[ocharles]

But almost all cases where the warning fires, the build would fail, no?

Sure, but I still don't think it's Haskell.nix's responsibility, much like it's not Cabal's responsibility.