Alex, hope you're well.
For some reason, the commit #783098 was not included in the 7.x-2.0-alpha3 release.
#783098 elliotttf: Introduce hook_feeds_user_processor_targets_alter(), mapper for...
Have a look. It is pretty obvious when the /mapper/profile.inc file in missing from the 7.x-2.0-alpha3 release download on the main drupal.org/project/feeds page.
Kindly advise. Many thanks.