when the app is opened with a custom url string, it crashes

If the app is already open, it works fine. If the app is not open, it crashes.

Because the crash requires the app to not be open, I cannot see the crash in the debugger.

i.e. if an app (mail) opens `appname://href?url=xyz` and my app is already open and has requested the `appname` schema, it will go to `xyz` just fine. However, if the app is not open, it will be launched and then it immediately crashes.

No files, tests, or entry points are named. Start by reproducing a cold launch with an appname://href?url=xyz URL and trace the app's URL-handling path during startup. Done means the app launches without crashing and routes the request to xyz, while preserving the existing behavior when already open.

Written by the indexing model from the issue text.