libclang.so.19.1.2 could not be opened: libz.so.1: cannot open shared object file: No such file or directory"

[CDaut]

When compiling a simple project I get the following error:

  thread 'main' panicked at /home/CDaut/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/bindgen-0.71.1/lib.rs:604:27:
  Unable to find libclang: "the `libclang` shared library at /home/CDaut/.rustup/toolchains/esp/xtensa-esp32-elf-clang/esp-19.1.2_20250225/esp-clang/lib/libclang.so.19.1.2 could not be opened: libz.so.1: cannot open shared object file: No such file or directory"
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

I am using the esp-dev overlay using the following flake:

{
  description = "A Nix-flake-based Rust ESP IDF development environment";

  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";

  outputs = { self, nixpkgs }:
    let
      supportedSystems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];

      nixpkgs-esp-dev = builtins.fetchGit {
        url = "https://github.com/mirrexagon/nixpkgs-esp-dev.git";

        # Optionally pin to a specific commit of `nixpkgs-esp-dev`.
        rev = "6c34f2436015eb6c107970d9b88f3d5d4600c6fa";
      };
      forEachSupportedSystem = f: nixpkgs.lib.genAttrs supportedSystems (system: f {
        pkgs = import nixpkgs { inherit system; overlays = [ (import "${nixpkgs-esp-dev}/overlay.nix") ]; };
      });
    in
    {
      devShells = forEachSupportedSystem
        ({ pkgs }: {
          default = pkgs.mkShell
            {
              packages = with pkgs; [
                esp-idf-full
                espflash
                cargo-espflash
                espup
                libz
              ];
            };
        });
    };
}

espup is installed at version 0.51.1
LIBCLANG_PATH is set to /home/CDaut/.rustup/toolchains/esp/xtensa-esp32-elf-clang/esp-19.1.2_20250225/esp-clang/lib as specified in ~/export-esp.sh

The specified directory contains the file libclang.so.19.1.2 so I really don't see why the file would not be found.

I guess this is related to this dev flake but am unsure. Any help is appreciated.

[BastienGermond]

Hi @CDaut,

This is an issue with NixOS and espup and not nixpkgs-esp-dev, there seems to be several users using espup on NixOS according to this comment that link to some possible solution provided by others. This flake looks like a good starting point.

In case you are still stuck, you should probably try to reach them on matrix and ask for help there.

I love the idea of esp-rs, but haven't dived into it yet, however feel free to let me know if the process of getting a working environment could be smoothed with changes in nixpkgs-esp-dev.