Historically this module depended on the OSSP UUID library, which accounts for the module's name. While the OSSP UUID library can still be found at it is not well maintained, and is becoming increasingly difficult to port to newer platforms. ​​uuid-ossp​​​ can now be built without the OSSP library on some platforms. On FreeBSD, NetBSD, and some other BSD-derived platforms, suitable UUID creation functions are included in the core ​​libc​​​ library. On Linux, macOS, and some other platforms, suitable functions are provided in the ​​libuuid​​​ library, which originally came from the ​​e2fsprogs​​​project (though on modern Linux it is considered part of ​​util-linux-ng​​​). When invoking ​​configure​​​, specify ​​--with-uuid=bsd​​​ to use the BSD functions, or ​​--with-uuid=e2fs​​​ to use ​​e2fsprogs​​​' ​​libuuid​​​, or ​​--with-uuid=ossp​​​ to use the OSSP UUID library. More than one of these libraries might be available on a particular machine, so ​​configure​​ does not automatically choose one.