old_contents: ##############################################################################
  # Copyright (c) 2013-2018, Lawrence Livermore National Security, LLC.
  # Produced at the Lawrence Livermore National Laboratory.
  #
  # This file is part of Spack.
  # Created by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
  # LLNL-CODE-647188
  #
  # For details, see https://github.com/spack/spack
  # Please also see the NOTICE and LICENSE files for our notice and the LGPL.
  #
  # This program is free software; you can redistribute it and/or modify
  # it under the terms of the GNU Lesser General Public License (as
  # published by the Free Software Foundation) version 2.1, February 1999.
  #
  # This program is distributed in the hope that it will be useful, but
  # WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and
  # conditions of the GNU Lesser General Public License for more details.
  #
  # You should have received a copy of the GNU Lesser General Public
  # License along with this program; if not, write to the Free Software
  # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ##############################################################################
  from spack import *
  import sys
  
  
  class Expat(AutotoolsPackage):
      """Expat is an XML parser library written in C."""
  
      homepage = "http://expat.sourceforge.net/"
      url      = "https://sourceforge.net/projects/expat/files/expat/2.2.2/expat-2.2.2.tar.bz2"
  
      # Version 2.2.2 introduced a requirement for a high quality
      # entropy source.  "Older" linux systems (aka CentOS 7) do not
      # support get_random so we'll provide a high quality source via
      # libbsd.
      # There's no need for it in earlier versions, so 'conflict' if
      # someone's asking for an older version and also libbsd.
      # In order to install an older version, you'll need to add
      # `~libbsd`.
      variant('libbsd', default=sys.platform != 'darwin',
              description="Use libbsd (for high quality randomness)")
      depends_on('libbsd', when="@2.2.1:+libbsd")
  
      version('2.2.2', '1ede9a41223c78528b8c5d23e69a2667')
      version('2.2.0', '2f47841c829facb346eb6e3fab5212e2')
  
      def configure_args(self):
          spec = self.spec
          args = []
          if '+libbsd' in spec and '@2.2.1:' in spec:
              args = ['--with-libbsd']
          return args
  
new_contents: ##############################################################################
  # Copyright (c) 2013-2018, Lawrence Livermore National Security, LLC.
  # Produced at the Lawrence Livermore National Laboratory.
  #
  # This file is part of Spack.
  # Created by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
  # LLNL-CODE-647188
  #
  # For details, see https://github.com/spack/spack
  # Please also see the NOTICE and LICENSE files for our notice and the LGPL.
  #
  # This program is free software; you can redistribute it and/or modify
  # it under the terms of the GNU Lesser General Public License (as
  # published by the Free Software Foundation) version 2.1, February 1999.
  #
  # This program is distributed in the hope that it will be useful, but
  # WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and
  # conditions of the GNU Lesser General Public License for more details.
  #
  # You should have received a copy of the GNU Lesser General Public
  # License along with this program; if not, write to the Free Software
  # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ##############################################################################
  from spack import *
  import sys
  
  
  class Expat(AutotoolsPackage):
      """Expat is an XML parser library written in C."""
  
      homepage = "https://libexpat.github.io/"
      url      = "https://github.com/libexpat/libexpat/releases/download/R_2_2_2/expat-2.2.2.tar.bz2"
  
      # Version 2.2.2 introduced a requirement for a high quality
      # entropy source.  "Older" linux systems (aka CentOS 7) do not
      # support get_random so we'll provide a high quality source via
      # libbsd.
      # There's no need for it in earlier versions, so 'conflict' if
      # someone's asking for an older version and also libbsd.
      # In order to install an older version, you'll need to add
      # `~libbsd`.
      variant('libbsd', default=sys.platform != 'darwin',
              description="Use libbsd (for high quality randomness)")
      depends_on('libbsd', when="@2.2.1:+libbsd")
  
      version('2.2.5', '789e297f547980fc9ecc036f9a070d49')
      version('2.2.2', '1ede9a41223c78528b8c5d23e69a2667')
      version('2.2.0', '2f47841c829facb346eb6e3fab5212e2')
  
      def url_for_version(self, version):
          url = 'https://github.com/libexpat/libexpat/releases/download/R_{0}/expat-{1}.tar.bz2'
          return url.format(version.underscored, version.dotted)
  
      def configure_args(self):
          spec = self.spec
          args = []
          if '+libbsd' in spec and '@2.2.1:' in spec:
              args = ['--with-libbsd']
          return args
  
subject: Fix for older systems, move to GitHub (#8135)