GitLab.com commit graph loads for a long time then throws a 500 error

When visitinghttps://gitlab.com/gitlab-org/gitlab/-/network/master, the graph never loads. Then, after a very long time, presumably a timeout error, the GET call to https://gitlab.com/gitlab-org/gitlab/-/network/master?format=json throws an error 500.

There are several layers of problems here.

  1. The call doesn’t return what it should
  2. When the call fails, the interface keeps displaying a loading animation instead of expressing that failure.
  3. The call’s response is HTML rather than JSON. It’s an AJAX call, and yet the response looks like this:
<!DOCTYPE html>
<html>
<head>
  <meta content="width=device-width, initial-scale=1, maximum-scale=1" name="viewport">
  <title>Something went wrong (500)</title>
  <!-- (...more HTML) -->

I would add screenshots, but the forum seems to throw errors anytime I try to upload anything, so…