I'm not able to follow the steps defined here:
https://sites.google.com/a/chromium.org/dev/chromium-os/developer-guide/gerrit-guide#TOC-Googler-Link-chromium.org-google.com-accounts

I get the error:
Error 422: Identity 'https://www.google.com/accounts/o8/id?g=AI2Pq9pVo0EkWUNxQVq3YxcLltMjm42EYAsv1Ii82P2TbwHAHrj0nHA' in use by another account

Endpoint: /config/server/email.confirm