Has there been an opera written about Liam O'Flaherty's book Famine?
After examining the research on Liam O'Flaherty and his novel Famine, it seems there are no theater productions of any kind, including operas, adapted from the book. I am not sure what prompted your question, but after checking the link below, I can understand any confusion on this issue.
It seems that a man named John Dunne has directed a folk opera called Regent's Canal. He has also written a work entitled Famine, and he has adapted another of O'Flaherty's books, The Informer. He has not, however, created an opera from that title.
Aside from this connection, I find no indication that O'Flaherty's Famine has been produced anywhere in any form.