The Pirates have announced that they've claimed catcher Eric Fryer from the Cardinals, clearing space on the 40-man roster by designating Rob Scahill for assignment. The Bucs haven't yet added Fryer to their active roster, but I assume that will happen soon.
The Bucs, of course, have had trouble with catcher depth, and Chris Stewart is on the active roster despite having had knee trouble recently. He has played sparingly in the past week, so he could end up on the DL. Also, as fun as Erik Kratz's few hits have been, he's been awful offensively, and Fryer is probably the better offensive player -- he's a career .270/.347/.354 hitter in the big leagues, providing a bit more on-base ability than you typically get from an otherwise replacement-level catcher.
Fryer, by the way, was designated for assignment last week. He played two seasons with Pittsburgh at the beginning of his career and made his big-league debut with the Bucs in 2011 when they were in the midst of their catcherpocalypse -- he was one of eight backstops the Pirates used that year. It appears his return to the Bucs will be under similar circumstances.