anchor.diff:  , cairo
   , double-conversion
   , gtest
  +, lib
   }:
   
   stdenv.mkDerivation rec {
  -  pname = "lib2geom-unstable";
  -  version = "2020-03-12";
  +  pname = "lib2geom";
  +  version = "1.1";
   
     outputs = [ "out" "dev" ];
   
     src = fetchFromGitLab {
       owner = "inkscape";
       repo = "lib2geom";
  -    rev = "226eb8c60f2af639d74a0229c0ba90e649e6451d";
  -    sha256 = "BSuqasBfig6HiKY/xtJm7CjbSaV8cW45ip59iEO5Es4=";
  +    rev = "refs/tags/${version}";
  +    sha256 = "sha256-u9pbpwVzAXzrM2/tQnd1B6Jo9Fzg6UZBr9AtUsNMfQ0=";
     };
  -
  -  patches = [
  -    # Re-enable assertions for tests to work
  -    # https://gitlab.com/inkscape/lib2geom/issues/5
  -    # https://gitlab.com/inkscape/lib2geom/merge_requests/17
  -    (fetchpatch {
  -      url = "https://gitlab.com/inkscape/lib2geom/commit/4aa78f52232682b353eb15c219171e466987bac7.patch";
  -      sha256 = "XsX8SPft0RwDemJujc8lierBe4s3iw8YkW4CSlY5LsY=";
  -    })
  -  ];
   
     nativeBuildInputs = [
       cmake
  
positive.code:     gtest
    ];
  
    cmakeBuildType = "RelWithDebugInfo"; # needed to keep assertions for tests working
  
    cmakeFlags = [
      "-DCMAKE_SKIP_BUILD_RPATH=OFF" # for tests
      "-DBUILD_SHARED_LIBS=ON"
    ];
  
    doCheck = true;
  
    meta = with stdenv.lib; {
      description = "Easy to use 2D geometry library in C++";
      homepage = "https://gitlab.com/inkscape/lib2geom";
      license = [ licenses.lgpl21 licenses.mpl11 ];
      maintainers = with maintainers; [ jtojnar ];
      platforms = platforms.unix;
    };
  
negative.code: { stdenv
  , fetchFromGitLab
  , cmake
  , ninja
  , pkg-config
  