clangd: Missing libz.so.1 when running clangd

[i-ilak]

Nixpkgs version

• Unstable (25.05)

Describe the bug

This issue came up when configuring nixvim. The same configuration was working until ~3 weeks.

Field	Description
Plugin	lsp
Nixpkgs	nixos-unstable
Home Manager	24.11-pre

Description

Whenever I run nixvim with my configuration on a C++ codebase, that starts lsp, I see an error of this form:

[ERROR][2025-03-18 15:28:34] .../vim/lsp/rpc.lua:770	"rpc"	"/nix/store/zqdqx2z1sng4yqqbwz8cga0dgwv3r37p-clang-tools-18.1.8/bin/clangd"	"stderr"	"/nix/store/zqdqx2z1sng4yqqbwz8cga0dgwv3r37p-clang-tools-18.1.8/bin/clangd: error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory\n"

Any idea why this shared object ins not in the LD_LIBRARY_PATH, or symlinked to the default locations Linux expects?

Steps to reproduce

The setup looks something like this (apologies if this is not the most minimal example, but I'm not 100% sure in which part the error happens...)

#flake.nix
nvim = nixvim'.makeNixvimWithModule {
  inherit pkgs;
  module = ./config;
};

#config/default.nix
{}:
{
  imports = [
    lsp.nix
  ];
}

#lsp.nix
{ pkgs
, ...
}: {
  plugins = {
    lsp-format = {
      enable = true;
    };
    lsp = {
      enable = true;
      servers = {
        clangd = {
          enable = true;
          package = pkgs.llvmPackages_18.clang-tools;
          cmd = [
            "clangd"
            "--offset-encoding=utf-16"
            "--background-index"
            "-j"
            "20"
            "--clang-tidy"
          ];
        };
      };
    };
  };
}

Which is the used like this in a configuration:

#flake.nix
{
  inputs = {
    nixpkgs-unstable.url = "github:nixos/nixpkgs/nixos-unstable";
    nixvim = {
      url = "github:i-ilak/nixvim-config";
      inputs.nixpkgs.follows = "nixpkgs-unstable";
    };
  }

  outputs = {
    ...
    } @ inputs 
  : {
      homeConfigurations = {
        # some deeper nesting, but in the end
        home.packages = [
                inputs.nixvim.packages.${pkgs.system}.default
        ];
      };
    };
}

Regardless of pkgs.clang-tools, or pkgs.llvmPackages_18.clang-tools, the issue persists.

Expected behaviour

For clangd to start normally and work.

Screenshots

No response

Relevant log output

Additional context

Double checking with nixvim maintainer here, indicate that this is a clangd issue.

System metadata

• system: "x86_64-linux"
• host os: Linux 6.8.0-51-generic, Ubuntu, 24.04.1 LTS (Noble Numbat), nobuild
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.25.3
• nixpkgs: /nix/store/shh5sdqk4h0s482fxyyw6v5hhljapby9-source

Notify maintainers

@Patryk27

---

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