old_contents: {
  	'repo_type' : 'git',
  	'run_post_patch' : [
  		'autoreconf -fiv',
  	],
  	'url' : 'https://github.com/mstorsjo/fdk-aac.git',
  	'configure_options' : '{autoconf_prefix_options}',
  	'_info' : { 'version' : None, 'fancy_name' : 'fdk-aac' },
  }
new_contents: {
  	'repo_type' : 'git',
  	'run_post_patch' : [
  		'autoreconf -fiv',
  	],
  	'url' : 'https://github.com/mstorsjo/fdk-aac.git',
  	# Note does not like to be compiled without optimisations: error: inlining failed in call to always_inline 'void fft_4(FIXP_DBL*)': indirect function call with a yet undetermined callee
  	# So make sure to empty the cflags or enable optimisations when your global c(xx)flags are defaulting to -0g/0:
  	# 'custom_cflag': '',
  	'configure_options' : '{autoconf_prefix_options}',
  	'_info' : { 'version' : None, 'fancy_name' : 'fdk-aac' },
  }
subject: add note about optimisations