i faced this error too. although i found a way around it, i don't consider the solution to be reliable. so here goes:
1. create a local_manifests folder in you <SOURCEDIR>/.repo directory
2. create a local_manifest.xml file in the previously created folder and open it to edit.
5. after repo sync finishes, add the contents of the downloaded DeskClock folder into the apporpriate directory in your <SOURCEDIR> aka 6ED428AB67C8B9F3/tdroid/tdroid-4.3_r1/.repo/projects/packages/apps/DeskClock
feed back if this works or if you've found more reliable solution :)