Help understanding error compiling Rust to WASM in NixOS

I’m working on a Rust library and I tried adding the following flake.nix file so I can get a development shell with all needed dependencies:

  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
  inputs.flake-utils.url = "github:numtide/flake-utils";

  outputs = { self, nixpkgs, flake-utils }:
    flake-utils.lib.eachSystem [ "x86_64-linux" ] (system:
      pkgs = import nixpkgs { inherit system; };
        devShells.default = pkgs.mkShell {
          nativeBuildInputs = with pkgs; [

When I try to compile to WASM by running cargo build --target wasm32-unknown-unknown --release, I get an error but I have no idea what it is saying.

   Compiling shared v0.1.0 (/home/user/src/lib)
error: linking with `rust-lld` failed: exit status: 1
  = note: LC_ALL="C" PATH="  <I omitted this due to the character limit on discourse>
  = note: rust-lld: error: unknown file type: /home/user/src/lib/target/wasm32-unknown-unknown/release/deps/libsecp256k1_sys-73da753343bc1281.rlib(lax_der_parsing.o)

error: could not compile `shared` due to previous error

Could someone please help me understand what this error means?
I am new to Rust so it could just be something simple I’m getting wrong.

I have also put a reproducible copy on GitHub: GitHub - emccorson/shared
I had to omit part of the error message due to the character limits on Discourse, but the full message is in the GitHub README.

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The build failed because the linker, lld, failed. The reason is likely in the rest of the log above.

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If you run file on the troublesome file, it may tell you it’s the wrong architecture. You can potentially try CC=clang cargo build (your args...) after adding clang to the shell. May also want to try CC=emcc if I recall correctly.

I was reminded of the gcc related issues I’ve had with trying to build wasm in the past by reading rust-lld: error: unknown file type: secp256k1.o · Issue #14 · bytecodealliance/wasi · GitHub

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Setting CC=clang worked! Thank you both for the help.

In my case, I ended up using pkgs.mkShell.override { stdenv = pkgs.clangStdenv; } which sets CC for me.