I found the method once before in the Apple Developer docs so I know it exists. Searching for it now online bears no fruit. Super grateful for any leads on this.

From the imagecapturecore-rs crate here: https://github.com/brandonhamilton/image-capture-core-rs/issues/7 Only didOpenSessionWithError fires when connecting a PTP (picture transfer protocol) device with a None for the error value and an NSArray with a count of 0. decl.add_method( sel!(device:didOpenSessionWithError:), device_did_open_session_with_error as extern "C" fn(&Object, Sel, id, id), ); println!(" 📸 add_method didCloseSessionWithError"); decl.add_method( sel!(device:didCloseSessionWithError:), device_did_close_session_with_error as extern "C" fn(&Object, Sel, id, id), ); println!(" 📸 add_method didRemoveDevice"); decl.add_method( sel!(didRemoveDevice:), device_did_remove_device as extern "C" fn(&Object, Sel, id), ); println!(" 📸 add_method withCompleteContentCatalog"); decl.add_method( sel!(withCompleteContentCatalog:), device_did_become_ready as extern "C" fn(&Object, Sel, id), ); Do I need to be using the fancier cameraDevice.requestOpenSession() with the callback function from here? https://developer.apple.com/documentation/imagecapturecore/icdevice/3142916-requestopensession As seen on StackOverflow: https://stackoverflow.com/questions/68978185/apple-ptp-withcompletecontentcatalog-not-firing-rust-obj-c