old_contents: ##############################################################################
  # Copyright (c) 2013-2016, 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/llnl/spack
  # Please also see the LICENSE file 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 *
  
  
  class YamlCpp(CMakePackage):
      """A YAML parser and emitter in C++"""
  
      homepage = "https://github.com/jbeder/yaml-cpp"
      url      = "https://github.com/jbeder/yaml-cpp/archive/yaml-cpp-0.5.3.tar.gz"
  
      version('0.5.3', '4e47733d98266e46a1a73ae0a72954eb')
  
      variant('fpic',    default=False,
              description='Build with position independent code')
  
      depends_on('boost', when='@:0.5.3')
  
      def cmake_args(self):
          spec = self.spec
          options = []
  
          if '+fpic' in spec:
              options.extend([
                  '-DCMAKE_POSITION_INDEPENDENT_CODE:BOOL=true'
              ])
  
          return options
  
new_contents: ##############################################################################
  # Copyright (c) 2013-2016, 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/llnl/spack
  # Please also see the LICENSE file 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 *
  
  
  class YamlCpp(CMakePackage):
      """A YAML parser and emitter in C++"""
  
      homepage = "https://github.com/jbeder/yaml-cpp"
      url      = "https://github.com/jbeder/yaml-cpp/archive/yaml-cpp-0.5.3.tar.gz"
  
      version('0.5.3', '4e47733d98266e46a1a73ae0a72954eb')
  
      variant('shared', default=True,
              description='Enable build of shared libraries')
      variant('fpic',    default=False,
              description='Build with position independent code')
  
      depends_on('boost', when='@:0.5.3')
  
      def cmake_args(self):
          spec = self.spec
          options = []
  
          if '+fpic' in spec:
              options.extend([
                  '-DCMAKE_POSITION_INDEPENDENT_CODE:BOOL=true'
              ])
          if '+shared' in spec:
              options.append('-DBUILD_SHARED_LIBS=ON')
          else:
              options.append('-DBUILD_SHARED_LIBS=OFF')
  
          return options
  
subject: add variant shared to yaml-cpp (#3254)