old_contents: class LibPngPackage (Package):
  	def __init__ (self):
  		Package.__init__(self, 'libpng', '1.4.12',
  										 sources = ['http://downloads.sourceforge.net/sourceforge/libpng/libpng-1.4.12.tar.xz'],
  										 configure_flags = ['--enable-shared'])
  
  LibPngPackage()
  
new_contents: class LibPngPackage (Package):
  	def __init__ (self):
  		Package.__init__(self, 'libpng', '1.4.12',
  										 sources = ['http://downloads.sourceforge.net/sourceforge/libpng/libpng-1.4.12.tar.xz'],
  										 configure_flags = ['--enable-shared'])
  
  		#This package would like to be built with fat binaries
  		if Package.profile.m64 == True:
  			self.fat_build = True
  
  	def arch_build (self, arch):
  		if arch == 'darwin-fat': #multi-arch  build pass
  			self.local_ld_flags = ['-arch i386' , '-arch x86_64']
  			self.local_gcc_flags = ['-arch i386' , '-arch x86_64', '-Os']
  			self.local_configure_flags = ['--disable-dependency-tracking']
  
  		Package.arch_build (self, arch)
  
  
  LibPngPackage()
  
subject: Enable fat binaries on libpng package