fl2k_* have libusb: error [op_dev_mem_alloc] alloc dev mem failed errno 12

Hi, I've compiled osmo-fl2k with libusb-1.0.22-1 and this happens when I tried to start fl2k_test: feanor@silmaril ~> fl2k_test -s 162e6 Using 6 zero-copy buffers libusb: error [op_dev_mem_alloc] alloc dev mem failed errno 12 Failed to allocate zero-copy buffer for transfer 4 Reporting PPM error measurement every 10 seconds... Press ^C after a few minutes. real sample rate: 15372775 current PPM: -905106 cumulative PPM: -905106 then when I try to connect red and ground output to oscilloscope, there is no output at all, even if I use fl2k_fm