new_contents: from spack import *
  
  class Jemalloc(Package):
      """jemalloc is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support."""
      homepage = "http://www.canonware.com/jemalloc/"
      url      = "https://github.com/jemalloc/jemalloc/releases/download/4.0.4/jemalloc-4.0.4.tar.bz2"
  
      version('4.0.4', '687c5cc53b9a7ab711ccd680351ff988')
  
      def install(self, spec, prefix):
          configure('--prefix=%s' % prefix)
  
          make()
          make("install")
  
subject: Add jemalloc package