I get very occasional exceptions in TrackingCollection - usually when the PR list is updating. Here's the details:

At TrackingCollection.cs line 476

System.ObjectDisposedException occurred
  HResult=-2146232798
  Message=Cannot access a disposed object.
Object name: 'TrackingCollection'.
  ObjectName=TrackingCollection
  Source=GitHub.Exports.Reactive
  StackTrace:
       at GitHub.Collections.TrackingCollection`1.RemoveItem(T item) in D:\projects\VisualStudio\src\GitHub.Exports.Reactive\Collections\TrackingCollection.cs:line 476
  InnerException: 

As you can see, the stack trace shows only the current method: RemoveItem.

This crashes VS.

Feels like a race condition between disposal of the current listeners in preparation for processing the new results and the current list still processing.

I tried my best to reproduce this bug or see how it could happen and I checked the master and maintainer-workflow-diff branches. The only usages of RemoveItem() I could find are wrapped in try/catch blocks that swallow exceptions of type ObjectDisposedException. I'm not sure how you are getting that exception.

Still getting this occasionally. The exception seems to be swallowed so it doesn't crash VS, but I'm worried that it might break the PR list.

Fixed by #742.