{ stdenv, fetchurl, cmake }:

stdenv.mkDerivation
  { name = "gflags-2.2.1";
    src = fetchurl
      { url = "https://github.com/gflags/gflags/archive/v2.2.1.tar.gz";
        sha256 = "03lxc2ah8i392kh1naq99iip34k4fpv22kwflyx3byd2ssycs9xf";
      };
    nativeBuildInputs = [ cmake ];
    # for case-insensitive filesystems
    prePatch = "mv BUILD BUILD.bazel";

    meta = with stdenv.lib; {
      description = "C++ library that implements commandline flags processing";
      homepage = "https://github.com/gflags/gflags";
      license = licenses.bsd3;
      platforms = platforms.unix;
    };
  }