If you follow a URL to a workspace build, and the workspace has been deleted, then the Coder dashboard loads the top and bottom bars, but spins forever in the main content page.

It issues a request to /api/v2/users/<user>/workspace/<workspace>/builds/<num>, which comes back 404. So, this appears to be a front-end bug, as we should be able to tell from the 404 that the build or workspace no longer exists.