1 diff --git a/libusb/os/darwin_usb.c b/libusb/os/darwin_usb.c
2 index b0ee5b2..fe40899 100644
3 --- a/libusb/os/darwin_usb.c
4 +++ b/libusb/os/darwin_usb.c
5 @@ -1449,8 +1449,14 @@ static int submit_bulk_transfer(struct usbi_transfer *itransfer) {
7 cInterface = &priv->interfaces[iface];
9 - (*(cInterface->interface))->GetPipeProperties (cInterface->interface, pipeRef, &direction, &number,
10 - &transferType, &maxPacketSize, &interval);
11 + ret = (*(cInterface->interface))->GetPipeProperties (cInterface->interface, pipeRef, &direction, &number,
12 + &transferType, &maxPacketSize, &interval);
15 + usbi_err (TRANSFER_CTX (transfer), "bulk transfer failed (dir = %s): %s (code = 0x%08x)", IS_XFERIN(transfer) ? "In" : "Out",
16 + darwin_error_str(ret), ret);
17 + return darwin_to_libusb (ret);
20 if (0 != (transfer->length % maxPacketSize)) {
21 /* do not need a zero packet */