Both libusbhid (system library) and libhidapi (3rd party library)
provide a function called hid_init. Dolphin was being linked to both.
The WiimoteScannerHidapi constructor was calling hid_init without
arguments. libusbhid's hid_init expects one argument (a file path).
It was being called as if it was defined without arguments, which
resulted in a garbage path being passed in, and because of that,
the Qt GUI was failing to launch with the following error:
'dolphin-emu-qt2: @ : No such file or directory'
Greg V