i can not comment directly about the 80D since i don't have one to try. dunno if there is some camera setting that's causing an incompatibility or if DCRAW simply does not support the 80D.
but each generation of canon cameras brings a slightly different CR2 format. for years Dave Coffin would reverse engineer these new CR2 formats and include support in dcraw.c, which is what PI uses to open camera raw files. Dave Coffin recently announced he's not going to maintain dcraw.c, so juan has decided to switch to libRaw, which is an open source project focused on the same problem. from his forum posts i understand that he's working on rolling libRaw into the next release of PI.
rob