anchor.diff:  
     cmakeFlags = [
       "-DPORTABLE=1"
  -    "-DWITH_JEMALLOC=0"
  +    "-DWITH_JEMALLOC=${if enableJemalloc then "1" else "0"}"
       "-DWITH_JNI=0"
       "-DWITH_BENCHMARK_TOOLS=0"
       "-DWITH_TESTS=1"
  
positive.code: 
    nativeBuildInputs = [ cmake ninja ];
  
    buildInputs = [ bzip2 lz4 snappy zlib zstd ];
  
    patches = [
      # Without this change private dependencies are exported.
  
negative.code: , snappy
  , zlib
  , zstd
  , enableJemalloc ? false, jemalloc
  , enableLite ? false
  , enableShared ? true
  }:
  