I initially attempted to create the EtherpadBackupBot Developer account using the https://idm.wikimedia.org/signup/ workflow. When doing that I entered a bad email address (bot.etherpad-backup@toolforge.org) for the new account. When I did not receive the email confirmation link to complete the account creation I realized my mistake. I then attempted to complete the registration again, this time with the correct email (etherpad-backup.bot@toolforge.org), but was told that the username was already taken. I double checked the LDAP directory to confirm that this was not true in the canonical data store.

Seeing no obvious way to correct the email in the pending account creation and wanting the account name to match the SUL account I had previously created, I decided to use Striker to create the Developer account instead. This action succeeded. Now that I have created the account I am able to use it with CAS-SSO and it's clients as expected. I figured out how to do this because I'm deeply informed about the Developer account ecosystem; I would not expect many other folks attempting to create a Developer account to be able to come up with a similar resolution without expert help.

I'm not exactly sure what the "best" fix is here, but I think there should be some way to either correct an unconfirmed account creation's email address or to abandon the creation entirely. The latter might be easier to implement via a confirmation screen showing the cn, uid, and mail attributes of the pending account along with a link or form that can be used to abandon the pending account. That could still catch out folks who close the confirmation screen before realizing their mistake, but even in that case it would seem reasonably possible for them to submit a support request and get help with the cancellation (or instructions on how to work around it as I found myself).