I'm installing on nanoBSD (a variant of FreeBSD). The configure/make/install process for libusb seems to go just fine. I see /usr/lib/include/usb.h and it's the same file as in the libusb package. When I run the backends configure, I get:
[...] checking usb.h usability... no checking usb.h presence... no checking for usb.h... no [...] *** Warning: sane-backends will be built without libusb support. There may *** be valid reasons to do so, e.g. if you don't use USB scanners or on *** platforms without libusb support but generally this means that you *** can't use USB devices with SANE. The most probable cause is that *** the libusb header file usb.h is not installed. If you use Linux *** you may need a package called 'libusb-dev', 'libusb-devel' or similar. [...] I've tried 'configure --includedir=/usr/local/include' and 'gmake -I/usr/local/include' to no avail. Not an expert in this process, so I'm grasping at straws.
