depot/third_party/nixpkgs/pkgs/applications/blockchains/polkadot/default.nix

{ clang
, fetchFromGitHub
, lib
, llvmPackages
, protobuf
, rustPlatform
, stdenv
, writeShellScriptBin
, Security
}:
rustPlatform.buildRustPackage rec {
  pname = "polkadot";
  version = "0.9.21";

  src = fetchFromGitHub {
    owner = "paritytech";
    repo = "polkadot";
    rev = "v${version}";
    sha256 = "HCj5WwfKa4QsfO+1u4ciukDg6Rzv/uvc8h+V/Duhksg=";

    # the build process of polkadot requires a .git folder in order to determine
    # the git commit hash that is being built and add it to the version string.
    # since having a .git folder introduces reproducibility issues to the nix
    # build, we check the git commit hash after fetching the source and save it
    # into a .git_commit file, and then delete the .git folder. we can then use
    # this file to populate an environment variable with the commit hash, which
    # is picked up by polkadot's build process.
    leaveDotGit = true;
    postFetch = ''
      ( cd $out; git rev-parse --short HEAD > .git_commit )
      rm -rf $out/.git
    '';
  };

  cargoSha256 = "tHU8KygIhJDgID/tGGssYTnY8raI5qTdLEDwOKox3No=";

  buildInputs = lib.optional stdenv.isDarwin [ Security ];

  nativeBuildInputs = [ clang ];

  preBuild = ''
    export SUBSTRATE_CLI_GIT_COMMIT_HASH=$(cat .git_commit)
    rm .git_commit
  '';

  LIBCLANG_PATH = "${llvmPackages.libclang.lib}/lib";
  PROTOC = "${protobuf}/bin/protoc";

  # NOTE: We don't build the WASM runtimes since this would require a more
  # complicated rust environment setup and this is only needed for developer
  # environments. The resulting binary is useful for end-users of live networks
  # since those just use the WASM blob from the network chainspec.
  SKIP_WASM_BUILD = 1;

  # We can't run the test suite since we didn't compile the WASM runtimes.
  doCheck = false;

  meta = with lib; {
    description = "Polkadot Node Implementation";
    homepage = "https://polkadot.network";
    license = licenses.gpl3Only;
    maintainers = with maintainers; [ akru andresilva asymmetric FlorianFranzen RaghavSood ];
    platforms = platforms.unix;
  };
}