foo.pp

  augeas { 'puppet-onboot':
    context => '/files/etc/default/puppet',
    incl    => '/etc/default/puppet', # http://projects.puppetlabs.com/issues/show/17486
    lens    => 'Shellvars.lns', # http://projects.puppetlabs.com/issues/show/17486
    changes => [
      'set START yes',
    ],
  } 

gistfile1.txt

Debug: Augeas[puppet-onboot](provider=augeas): Opening augeas with root /, lens path , flags 32
Debug: Augeas[puppet-onboot](provider=augeas): Augeas version 0.10.0 is installed
Warning: Augeas[puppet-onboot](provider=augeas): Loading failed for one or more files, see debug for /augeas//error output
Debug: Augeas[puppet-onboot](provider=augeas): /augeas/files/etc/default/whoopsie/error/pos = 1
Debug: Augeas[puppet-onboot](provider=augeas): /augeas/files/etc/default/whoopsie/error/line = 2
Debug: Augeas[puppet-onboot](provider=augeas): /augeas/files/etc/default/whoopsie/error/char = 0
Debug: Augeas[puppet-onboot](provider=augeas): /augeas/files/etc/default/whoopsie/error/lens = /usr/share/augeas/lenses/dist/shellvars.aug:138.12-.89:
Debug: Augeas[puppet-onboot](provider=augeas): /augeas/files/etc/default/whoopsie/error/message = Syntax error
Debug: Augeas[puppet-onboot](provider=augeas): Will attempt to save and only run if files changed
Debug: Augeas[puppet-onboot](provider=augeas): sending command 'set' with params ["/files/etc/default/puppet/START", "yes"]
Debug: Augeas[puppet-onboot](provider=augeas): Skipping because no files were changed
Debug: Augeas[puppet-onboot](provider=augeas): Closed the augeas connection