Exception: Reflexive edges in graphs are not allowed

[CharliePoole]

This error is occurring when an invalid target task is entered for the --target option. It seems that the search for a task goes deeper in this case and some recursion occurs. I suspect this is due to the code that allows multiple targets by creating a synthetic target of the form A+B+C. The implementation may need to be changed or possibly the feature may need to be removed.