树莓派运行命令时提示cannot find webcams

我正在通过edge impulse来实现图像识别 在命令行输入edge-impulse-linux时 提示cannot find webcams但是我的摄像头是能正常拍照的

edge-impulse使用的是opencv调取摄像头，看一下opencv安装好了么？

源码部分

def get_webcams():
    port_ids = []
    for port in range(5):
        print("Looking for a camera in port %s:" %port)
        camera = cv2.VideoCapture(port)
        if camera.isOpened():
            ret = camera.read()[0]
            if ret:
                backendName =camera.getBackendName()
                w = camera.get(3)
                h = camera.get(4)
                print("Camera %s (%s x %s) found in port %s " %(backendName,h,w, port))
                port_ids.append(port)
            camera.release()
    return port_ids
....
....
    with ImageImpulseRunner(modelfile) as runner:
        try:
            model_info = runner.init()
            print('Loaded runner for "' + model_info['project']['owner'] + ' / ' + model_info['project']['name'] + '"')
            labels = model_info['model_parameters']['labels']
            if len(args)>= 2:
                videoCaptureDeviceId = int(args[1])
            else:
                port_ids = get_webcams()
                if len(port_ids) == 0:
                    raise Exception('Cannot find any webcams')
                if len(args)<= 1 and len(port_ids)> 1:
                    raise Exception("Multiple cameras found. Add the camera port ID as a second argument to use to this script")
                videoCaptureDeviceId = int(port_ids[0])

Linux make 时会出现
/usr/bin/ld: cannot find -lxxx
我遇到时 这个XXX(库的名字)已经存在 但不时在lib库下 ，原来在Linux里gcc时是不需要加-lXXX的，会自动编译，加了反倒编译不过，我把makefile里的-lXXX去掉后就通过了。