Merge check gets stuck indefinitely

[BrettCleary]

Select Topic Area

Bug

Body

When merging down from main with the "Update branch" button, I see the error below and the "Checking for the ability to merge automatically..." message and spinner persist indefinitely.

occurred on this PR

Same behavior with the old merge experience

occurred on this PR.

Closing and re-opening the PR does not fix. The only fix is opening a new PR with the same branch which of course is not a good flow.

[github-actions[bot]]

💬 Your Product Feedback Has Been Submitted 🎉

Thank you for taking the time to share your insights with us! Your feedback is invaluable as we build a better GitHub experience for all our users.

Here's what you can expect moving forward ⏩

• Your input will be carefully reviewed and cataloged by members of our product teams. 
  • Due to the high volume of submissions, we may not always be able to provide individual responses.
  • Rest assured, your feedback will help chart our course for product improvements.
• Other users may engage with your post, sharing their own perspectives or experiences. 
• GitHub staff may reach out for further clarification or insight. 
  • We may 'Answer' your discussion if there is a current solution, workaround, or roadmap/changelog post related to the feedback.

Where to look to see what's shipping 👀

• Read the Changelog for real-time updates on the latest GitHub features, enhancements, and calls for feedback.
• Explore our Product Roadmap, which details upcoming major releases and initiatives.

What you can do in the meantime 💻

• Upvote and comment on other user feedback Discussions that resonate with you.
• Add more information at any point! Useful details include: use cases, relevant labels, desired outcomes, and any accompanying screenshots.

As a member of the GitHub community, your participation is essential. While we can't promise that every suggestion will be implemented, we want to emphasize that your feedback is instrumental in guiding our decisions and priorities.

Thank you once again for your contribution to making GitHub even better! We're grateful for your ongoing support and collaboration in shaping the future of our platform. ⭐

[indraxi]

Check for Large Diffs: If your branch has a substantial number of changes compared to the main branch, GitHub might struggle to compute the mergeability, leading to the hanging message. In such cases, consider breaking down your changes into smaller, more manageable pull requests.