Does not work properly on macOS 10.13 & 10.14.

[hwaki]

Installed libusb and uhubctl with Homebrew as instructed. The command "uhubctl" nor "uhubctl -f" does not show any hub info; not even a message such as "No compatible smart hubs detected!". The command just stuck and I have to terminate the command by ctrl-c key. Tried on two different mac (OS 10.13 and 10.14) and both act the same. The only thing that is working is the command with -h (help) and -v (version) options. What am I doing wrong?

[mvp]

Which version of uhubctl and libusb you have? You should have uhubctl 2.4.0 and libusb 1.0.26.
Unfortunately right now I only have access to MacOS 11.x and 12.x devices. I do remember that it worked fine on 10.13 (high sierra) and 10.14 (mojave) for me, but back then I used older version of libusb (1.0.21) - try linking with that.

[hwaki]

I had uhubctl 2.4.0 and libusb 1.0.26 (installed via homebrew). I uninstalled them and tried MacPorts instead and everything worked fine even with the same version of uhubctl and libusb.

[hwaki]

The command worked for a few times and then stopped working. So something else should causing this issue. What's the best way to trace the cause of the issue?

[mvp]

Perhaps you could try debugging it under gdb? Since you are running on MacOS 10.x,
you should be able to just do this:

git clone https://github.com/mvp/uhubctl
cd uhubctl
make
brew install gdb
gdb ./uhubctl
b main
r
<use n or s from here to debug and check variables using p>

This will not work on MacOS 11.x+ out of the box - you have to codesign gdb, which is quite painful.

However, you can always sprinkle uhubctl.c with printf() statements here and there and hopefully understand where it gets stuck.

[mvp]

If gdb gives you issues with codesigning, I checked that lldb works instead just fine (lldb is LLVM's gdb replacement provided by Apple and is already codesigned).
You can debug with:

git clone https://github.com/mvp/uhubctl
cd uhubctl
make
lldb ./uhubctl
b main
r
<use n or s from here to debug and check variables using p>

[hwaki]

I'm still working on the debuging but seems like the program gets stuck at following libusb function call when it tries to get hub info.
* By the way, tested uhubctl (via homebrew) with a few different macs running macOS Monterey/Catalina/Mojave/High Sierra, and it only worked under Monterey.

len = libusb_control_transfer(devh,
            LIBUSB_ENDPOINT_IN | LIBUSB_REQUEST_TYPE_CLASS
                               | LIBUSB_RECIPIENT_DEVICE, /* hub status */
            LIBUSB_REQUEST_GET_DESCRIPTOR,
            desc_type << 8,
            0,
            buf, sizeof(buf),
            USB_CTRL_GET_TIMEOUT
        );

====================================

* thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGSTOP
  * frame #0: 0x00007fff7366336a libsystem_kernel.dylib`poll + 10
    frame #1: 0x00000001000f7a70 libusb-1.0.0.dylib`usbi_wait_for_events + 94
    frame #2: 0x00000001000f661b libusb-1.0.0.dylib`handle_events + 200
    frame #3: 0x00000001000f62bf libusb-1.0.0.dylib`libusb_handle_events_timeout_completed + 328
    frame #4: 0x00000001000f6af2 libusb-1.0.0.dylib`libusb_handle_events_completed + 37
    frame #5: 0x00000001000f7541 libusb-1.0.0.dylib`sync_transfer_wait_for_completion + 72
    frame #6: 0x00000001000f73f0 libusb-1.0.0.dylib`libusb_control_transfer + 284
    frame #7: 0x000000010000399f uhubctl`get_hub_info(dev=0x00000001005006f0, info=0x00007ffeefbff4a8) at uhubctl.c:391:15
    frame #8: 0x0000000100002dae uhubctl`usb_find_hubs at uhubctl.c:713:14
    frame #9: 0x00000001000019a9 uhubctl`main(argc=1, argv=0x00007ffeefbff950) at uhubctl.c:1017:10
    frame #10: 0x00007fff735263d5 libdyld.dylib`start + 1

====================================

    frame #0: 0x00007fff7366336a libsystem_kernel.dylib`poll + 10
libsystem_kernel.dylib`poll:
->  0x7fff7366336a <+10>: jae    0x7fff73663374            ; <+20>
    0x7fff7366336c <+12>: movq   %rax, %rdi
    0x7fff7366336f <+15>: jmp    0x7fff7365b41d            ; cerror
    0x7fff73663374 <+20>: retq   

[mvp]

It seems that this is issue with your hub or libusb/MacOS inability to get hub descriptors. This function simply sends control request to the hub to identify itself - like tell vendor/product or serial number strings. Can you try with different hub(s)?

[hwaki]

I tested it without an external USB hub connected but the results were the same. I haven't been able to figure out the cause of the hang with libusb 1.0.26 but I tested uhubctl 2.4 with older version of libusb's and here are the result.

uhubctl 2.4 worked with following libusb version

macOS ver	libusb ver
Monterey	libusb 1.0.26
Catalina	libusb 1.0.23
Mojave	libusb 1.0.22
High Sierra	libusb 1.0.22