Errors on joinSession() are not correctly logged

[bojcicm]

If error occurs after line

yield e.joinSession()

In catch block it doesn't display error correctly.
On UI it will display message UIKit: [Object object]
No logs in console, couldn't figure out what was wrong.

In minified file I had to update catch logic after joinSession()
Instead of

catch(i) {
  e.error.throw("UIKit", i);
  e.isLoading = false;
}

I have changed it to

catch(i) {
  e.error.throw("UIKit", i.reason);
  console.error(i);
  e.isLoading = false;
}