CIDetector crashing while processing CMSampleBuffer

Problem: I am trying to get facial features through CIDetector from CMSampleBuffer from AVCaptureVideoDataOutput. On execution of the program, 9 out of 10 time the program crashes and only once it runs fine.

Expected Output: Run without crash and print "Happy" on feature detection.

Code:

func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
    
    let imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer)!
    let opaqueBuffer = Unmanaged<CVImageBuffer>.passUnretained(imageBuffer).toOpaque()
    let pixelBuffer = Unmanaged<CVPixelBuffer>.fromOpaque(opaqueBuffer).takeUnretainedValue()
    let sourceImage = CIImage(cvPixelBuffer: pixelBuffer, options: nil)
    let options = [CIDetectorSmile : true as AnyObject, CIDetectorEyeBlink: true as AnyObject, CIDetectorImageOrientation : 6 as AnyObject]
    
    // The detector is nil
    let detector = CIDetector(ofType: CIDetectorTypeFace, context: nil, options: options) 
    let features = detector!.features(in: sourceImage, options: options)

        for feature in features as! [CIFaceFeature] {

            if (feature.hasSmile) {
                printLog(item: "HAPPY")
            }
        }
}

Crashlog : Unexpectedly found nil while unwrapping an Optional value. The detector is nil

Would love help and further pointers.

The return is optional and sampleBuffer is called way too heavy you can only do this

if let detector = CIDetector(ofType: CIDetectorTypeFace, context: nil, options: options) {
    let features = detector.features(in: sourceImage, options: options) 
    for feature in features as! [CIFaceFeature] { 
        if (feature.hasSmile) {
            printLog(item: "HAPPY")
        }
    }
}