I’m pleased to announce version 1.5.3 of libbson and libmongoc, the libraries constituting the MongoDB C Driver.


This is a patch release that fixes a build error with MinGW on Windows.


This release fixes the following bugs:

  • CDRIVER-1964: Windows CA stores should be opened with read-only flag
  • CDRIVER-1970: Conflicting symbols MAX and MIN on FreeBSD
  • CDRIVER-1971: Missing exports of some GridFS functions
  • CDRIVER-1975: Mixed $ and non-$ query operators should be allowed

There was a glitch on the road from 1.5.1 to this release, 1.5.3. We tried to update the driver to connect to IPv6-only MongoDB servers by hostname, (CDRIVER-1972). For example, if the server listening on example.com only accepts IPv6 connections, we should be able to connect to it with the URI mongodb://example.com. Unfortunately we messed this up: if the server only accepts IPv4, we’d try IPv6 first, time out, and we did not then fall back to IPv4 (CDRIVER-1988).

That bug was released in version 1.5.2 yesterday. I’ve pulled 1.5.2 from GitHub. Version 1.5.3 reverts to the old behavior: it connects to MongoDB over IPv6 if given an IPv6 connection string like mongodb://[::1], and requires an IPv4 connection when given a hostname like mongodb://example. At some point we’ll implement the desired behavior correctly.


— A. Jesse Jiryu Davis

Image: Sea monster. Ulisse Aldrovandi, 17th Century