[BUG] Unable to build hdk_derive for test

[mattyg]

[BUG] Unable to build hdk_derive for test

[ThetaSinner]

Okay so the reason that this is happening is super simple, I did it wrong :)

So the stdenv makes Nix use mold as the linker but it does not make Rust use it. I'm not sure why the way I tested it resulted in a successful build but I'm assuming I got a step wrong somewhere.

A working flake is:

{
  description = "Template for Holochain app development";

  inputs = {
    versions.url  = "github:holochain/holochain?dir=versions/weekly";

    holochain-flake.url = "github:holochain/holochain";
    holochain-flake.inputs.versions.follows = "versions";

    nixpkgs.follows = "holochain-flake/nixpkgs";
    flake-parts.follows = "holochain-flake/flake-parts";
  };

  outputs = inputs:
    inputs.flake-parts.lib.mkFlake
      {
        inherit inputs;
      }
      {
        systems = builtins.attrNames inputs.holochain-flake.devShells;
        perSystem =
          { inputs'
          , config
          , pkgs
          , system
          , ...
          }: {
            devShells.default = pkgs.mkShell.override { stdenv = inputs'.holochain-flake.devShells.holonix.stdenv; } {
              inputsFrom = [ inputs'.holochain-flake.devShells.holonix ];
              packages = [
                pkgs.nodejs-18_x
                # more packages go here
              ];
              shellHook = '' export RUSTFLAGS="-C link-arg=-fuse-ld=mold" '';
            };
          };
      };
}

So creating a new shell and using inputsFrom does not inherit the stdenv, mold won't be available. Then the shellHook is also necessary to tell Rust to use the provided mold.

Note that this flake will only work correctly on Linux so it's not really fit for purpose at the moment. It is useful for understanding the missing pieces but that's about it for the moment.

I'll have a think about a reasonable way to put this together. I think an alternative mkShell exposed from this repo might be good so we can customise for the user and the RUSTFLAGS we can set in the holonix shell hook but that's a bit risky for clashes with project settings...

[steveej]

thanks for updating the example repo!

i now have a reproduction of the issue, identified the root cause, and also found a workaround that we can apply to holonix.

the root cause is that holochain's test_utils feature effectively introduces a dependency on openssl with the default feature set, causing it to link against the system's openssl.

openssl v0.10.57
└── openssl feature "default"
    └── native-tls v0.2.11
        └── native-tls feature "default"
            ├── hyper-tls v0.5.0
            │   └── hyper-tls feature "default"
            │       └── reqwest v0.11.17
            │           ├── reqwest feature "__tls"
            │           │   └── reqwest feature "default-tls"
            │           │       └── reqwest feature "default"
            │           │           ├── kitsune_p2p_bootstrap v0.2.0-beta-dev.12
            │           │           │   ├── kitsune_p2p_bootstrap feature "default"
            │           │           │   │   ├── holochain v0.3.0-beta-dev.21
            │           │           │   │   │   ├── holochain feature "arbitrary"
            │           │           │   │   │   │   └── holochain feature "test_utils"
            │           │           │   │   │   │       [dev-dependencies]
            │           │           │   │   │   │       └── posts v0.0.1 (/home/steveej/src/others/bug-reproduction-serialize-unit-value/dnas/demo/zomes/coordinator/posts)
            │           │           │   │   │   │           └── posts feature "default" (command-line)

a possible workaround to holonix is to add openssl to LD_LIBRARY_PATH. i'm preparing that workaround in #2942.

[steveej]

fixed by #2942 with a fix to CI regression tests coming in #3048.

@mattyg after a nix flake update this ought to just work should work for you now too 🙂 please re-open or file a new issue if that's not the case.

[ThetaSinner]

It looks like the stdenv part is being looked at here #2942

[steveej]

i implemented a basic version of switching to mold on linux in the devShells.

@mattyg please test it on the repo, see the changes here. either me or GitHub are confused as it won't let me create a PR from my branch.

[mattyg]

i implemented a basic version of switching to mold on linux in the devShells.

@mattyg please test it on the repo, see the changes here. either me or GitHub are confused as it won't let me create a PR from my branch.

Thank you! Now the tests build and run but I'm getting this error linking to libssl

/home/matt/Projects/Holochain/bug-reproduction-serialize-unit-value/target/debug/deps/test-fc6f51688c9afa1e: error while loading shared libraries: libssl.so.3: cannot open shared object file: No such file or directory

[steveej]

i can't reproduce the above. i'm getting seemingly unrelated compiler errors:

error[E0277]: the trait bound `SweetCell: hdk::prelude::Serialize` is not satisfied
  --> dnas/demo/zomes/coordinator/posts/tests/test.rs:28:50
   |
28 |         .call(&alice.zome("posts"), "get_usize", ah)

it'd be great if you could lay out the exact revision of this reop and commands that you use to reproduce the error you're seeing.

[mattyg]

sorry i had local changes to the example repo -- pushed

[steveej]

@mattyg would you mind double-checking that https://github.com/steveej/bug-reproduction-nix-zome-build/tree/new-main works as expected for you now?

[mattyg]

yep it works now - thank you!