new_contents: from spack import *
  
  class Muparser(Package):
      """C++ math expression parser library."""
      homepage = "http://muparser.beltoforion.de/"
      url      = "https://github.com/beltoforion/muparser/archive/v2.2.5.tar.gz"
  
      version('2.2.5', '02dae671aa5ad955fdcbcd3fee313fb7')
  
      def install(self, spec, prefix):
          options = ['--disable-debug',
                     '--disable-dependency-tracking',
                     '--prefix=%s' % prefix]
  
          configure(*options)
  
          make()
          make("install")
  
subject: add muparser package