For the HHVM driver I need both libbson and libmongoc, and my source code is organised like:

.
├── libbson
├── libmongoc
├── src
│   └── MongoDB
└── tests

However, when you run autogen.sh for libmongoc - it insists on pulling in its own libbson submodule clone in libmongoc/src/libbson.

./configure has an option " --with-libbson=[auto/system/bundled]", which I would like to see extended to either of:

• a specific directory, so I can have libbson wherever I want
• "parent" as an option (or "sibling", or whatever name you come up with), to allow for libbson to live in the same directory as libmongoc does as per above directory tree.