core: include sys/time.h on any GNU libc OS GNU libc provides sys/time.h, so unconditionally include it when using that libc. Since sys/time.h is already included on a number of OSes, include it to minimize the differences between OSes when using libusb. Arguably, sources using functions from sys/time.h (such as gettimeofday) ought to already include it on their own; OTOH, let's avoid making such issues OS-specific.
libusb is a library for USB device access from Linux, macOS, Windows, OpenBSD/NetBSD and Haiku userspace. It is written in C (Haiku backend in C++) and licensed under the GNU Lesser General Public License version 2.1 or, at your option, any later version (see COPYING).
libusb is abstracted internally in such a way that it can hopefully be ported to other operating systems. Please see the PORTING file for more information.
libusb homepage: http://libusb.info/
Developers will wish to consult the API documentation: http://api.libusb.info
Use the mailing list for questions, comments, etc: http://mailing-list.libusb.info
(Please use the mailing list rather than mailing developers directly)