As noted on http://bugs.darcs.net/issue636 .

Tobias Herp wrote:
> Simon Michael schrieb:
>> Sorting roundup-admin "list user" by username, I see a lot of users 
>> appearing two or more times with near-consecutive user numbers.
> 
> Sounds like some requests have been sent multiple times; anyway, it
> shouldn't have been possible to add users sharing the same email
> addresses. Where did your users come from?
> 
>> Any tips on how to clean up or whether it is 
>> even a problem ? This is roundup 1.3.9.
> 
> Well, of course it might be a problem to have multiple users for one
> person; a person using one of them would e.g. never see the issues
> assigned to the others.
> 
> IMO, you need to specify the user objects you want to keep and create a
> list of duplicate objects for each of them; then, create a script which
> changes all links to the duplicates, and finally retires the dupes.
> 
> HTH,

Worth fixing

Roundup user creations during the first half of 2008 sometimes repeated
themselves after a split-second, probably due to some error condition, causing
these duplicates. I've now retired all duplicate users, so each username is now
unique. Following Tobias' suggestion I consolidated all cross-references from
issues and messages onto the primary (first created) user, then retired the
rest, so you shouldn't notice any disruption, except possibly some reordering of
messages - if so please report it here.