Debugging on watchOS device

Notes

• Make sure the phone is connected to wifi (same network as the mac).
• Make sure "Debug over WiFi" is enabled for both the watch app project and the watch extension project
• Debugging is slow. In my tests it takes ~60 seconds + upload time (depends on the size of the app; calculate approx 60 seconds per 10mb for the watch app (myapp.app/Watch)) to hit a breakpoint at launch.
• It's flaky. If it doesn't work, try again a couple of times.
• Always use the watch charger. Without the charger it's much flakier.

Known issues

• Symptom: the app doesn't launch on the watch (just a spinning wheel)

  This is printed to the device log (the signifant string is other version in use):

  Aug 30 13:37:44 WatchA gizmoappd[93] : (Error) WatchKit: <SPGizmoPlugInManager.m __72-[SPGizmoPlugInManager beginUsingExtension:serverIdentifier:completion:]_block_invoke:1120> could not activate plugin com.xamarin.testapp.watchkitapp.watchkitextension (error:Error Domain=PlugInKit Code=16 "other version in use: <PKPlugin: 0x15da4f80 com.xamarin.testapp.watchkitapp.watchkitextension(${BundleShortVersion}) (guid) 0(0) /private/var/containers/Bundle/Application/(guid)/unified-test-appsrtfh.app/PlugIns/testapp.appex>" UserInfo={NSLocalizedDescription=other version in use: <PKPlugin: 0x15da4f80 com.xamarin.testapp.watchkitapp.watchkitextension(${BundleShortVersion}) (guid) 0(0) /private/var/containers/Bundle/Application/(guid)/testapp.app/PlugIns/testapp.appex>})

  Workaround: reboot the watch

When something doesn't work

• Make sure you have the latest versions of everything (Xcode, Xamarin Studio, Xamarin.iOS) installed.
• Reboot everything (watch + phone + mac) and try again.
• File a bug (see below for information to include in the bug report).

Logs to fetch when filing a bug

• Execute the following in a terminal:

    echo 123456789 > ~/.mlaunch-verbosity
  

• Make sure to capture the device log

  • If using watchOS 3, the device log has to be enabled by installing the sysdiagnose profile that can be downloaded here: https://developer.apple.com/bug-reporting/profiles-and-logs/?platform=watchos. Follow Apple's Instructions to install it (except that you can just open that page on the phone and download the profile there, no need to email it to yourself).

  • If using watchOS 3, you might also want to capture the device log by invoking mlaunch directly and redirecting to a file (because there will be a lot of output once the sysdiagnose profile is installed):

    /Library/Frameworks/Xamarin.iOS.framework/Versions/Current/bin/mlaunch --logdev --devname "Name of device (UUID works as well)" > mylog.txt
    

  • You can get the name of the device by executing:

    /Library/Frameworks/Xamarin.iOS.framework/Versions/Current/bin/mlaunch --listdev
    

• Reproduce again (you'll get a lot of output in the Application Output if things are working correctly).

• Lower the verbosity again:

    rm -f ~/.mlaunch-verbosity
  

• Attach both the device log and the Application Output to the bug (as attachments / gists).