I just created an account for sj-bot on commons, while logged in as sj, via special:userlogin. Then I registered it via pywikipediabot (from the command line) and tried to log in for the first time to verify that I'd received a new message about being registered successfully. I get this error:
"
A database query syntax error has occurred. This may indicate a bug in the software. The last attempted database query was:
(SQL query hidden)
from within function "User::addToDatabase". Database returned error "1062: Duplicate entry 'Sj-bot' for key 2 (10.0.0.241)".
"
Version: unspecified
Severity: enhancement