Warn the user about using --changed or specs along with --owner-of

src/python/pants/init/target_roots_calculator.py

@@ -251,4 +251,4 @@ def iter_owner_target_addresses(self, owned_files):
     return
 
   def owner_target_addresses(self, owner_request):
-    return list(self.iter_owner_target_addresses(owner_request))
+    return list(self.iter_owner_target_addresses(owner_request))

src/python/pants/option/global_options.py

@@ -183,8 +183,11 @@ def register_bootstrap_options(cls, register):
     register('--subproject-roots', type=list, advanced=True, fromfile=True, default=[],
              help='Paths that correspond with build roots for any subproject that this '
                   'project depends on.')
-    register('--owner-of', help='Select the targets that own these files', type=list, default=[],
-             metavar='<path>')
+    register('--owner-of', type=list, default=[], metavar='<path>',
+             help='Select the targets that own these files.'
+                  'This is the third target calculation strategy along with the --changed'
+                  'options and specifying the targets directly. These three types of target'
+                  'selection are mutually exclusive.')
 
     # These logging options are registered in the bootstrap phase so that plugins can log during
     # registration and not so that their values can be interpolated in configs.