'Parameter passed to function is invalid.', code: 7 with PGR Chameleon

[riklaunim]

I'm trying to use the library with old USB2 Chameleon camera on Linux. It works with FlyCap2 but with pyflycap2

    from pyflycap2.interface import Camera
    c = Camera(serial=11444408) # serial no from GUI picker

I get

'Parameter passed to function is invalid.', code: 7
  File "pyflycap2/includes/cy_compat.pxi", line 6, in pyflycap2.interface.check_ret

CameraContext on get_num_cameras returns 1 but if I try get_device_guid_from_index with 0 or 1 I get the same exception.

[matham]

I only tested with ethernet cameras, so I'm not sure this supports the USB cameras.