In 2.6~pre, the xhc-hb04 driver requires libusb-1.0-0-dev to build, and our debian package build-depends on it. This means 2.6~pre no longer builds on Hardy.
Teach src/configure to check for libusb-1.0-0-dev and disable the xhc-hb04 driver if it's not found, then teach debian/configure to only build-depend on it on lucid & newer.