Image description: black and white mosaic of a creature with the head and paws of a lion and the lower body and tail of a snake, with three-lobed fish tail. It appears to have cartoonish ripple lines drawn with mosaic tile around its paws showing it is paddling, and lines beneath it showing forward motion.

I’m pleased to announce version 1.9.1 of libbson and libmongoc, the libraries constituting the MongoDB C Driver.


This release reverts a changed macro definition that broke API compatibility, and fixes an off-by-one error in bson_append_regex that resulted in corrupt BSON, thanks to Derick Rethans.


We fixed a bug that caused session ID to be included in authentication and server monitoring commands. Thanks to Jeremy Mikola for finding and fixing the issue.


  — A. Jesse Jiryu Davis

Image: Sea-monster, detail of a mosaic representing Poseidon. Room 4 of the Baths of Neptune, Ostia Antica, Latium, Italy.