I think this is strictly a bug in the gitcreds package, but rhub2 doesn't seem to recognize it even though I registered the secret in the GitHub CLI.
$ gh secret list
NAME UPDATED
RHUB2 about 3 minutes ago
> rhub2::rhub_doctor()
✔ Found R package at /workspaces/httpgd.
✔ Found git repository at /workspaces/httpgd.
→ Do you have a GitHub personal access token (PAT)?
This hangs:
> gitcreds::gitcreds_get()