I have never heard (or read) of it other than in the context of The Clancy Brothers - who always credited it to Seamus McGraht (of whom I know nothing). The words have no trace ot traditonal folk-processing.

Regards

p.s.Given the Clancy Brothers connection, my instinct is that the "Carrick" referred to is Carrick-on-Suir rather than Carrick-on-Shannon, as some sources seem to think.