Topic on Extension talk:UserMerge

See also the respective mailing list thread

My config:

Product	Version
MediaWiki	1.33.1 (d35fba2) 15:11, December 17, 2019
PHP	7.2.17-0ubuntu0.18.04.1 (apache2handler)
MariaDB	10.1.38-MariaDB-0ubuntu0.18.04.1

UserMerge

1.10.1 (4b7feed) 08:17, July 24, 2019

trying to delete a user (merging it to Anonymous) I get this error and the following backtrace:

UserMerge CannotCreateActorException from line 2516 of /var/www/w/includes/user/User.php: Cannot create an actor for a usable name that is not an existing user.

Backtrace:

#0 /var/www/w/extensions/UserMerge/includes/MergeUser.php(378): User->getActorId(Wikimedia\Rdbms\DatabaseMysqli)

#1 /var/www/w/extensions/UserMerge/includes/MergeUser.php(50): MergeUser->mergeDatabaseTables(string)

#2 /var/www/w/extensions/UserMerge/includes/SpecialUserMerge.php(135): MergeUser->merge(User, string)

#3 /var/www/w/includes/htmlform/HTMLForm.php(660): SpecialUserMerge->onSubmit(array, OOUIHTMLForm)

#4 /var/www/w/includes/htmlform/HTMLForm.php(552): HTMLForm->trySubmit()

#5 /var/www/w/includes/htmlform/HTMLForm.php(567): HTMLForm->tryAuthorizedSubmit()

#6 /var/www/w/includes/specialpage/FormSpecialPage.php(184): HTMLForm->show()

#7 /var/www/w/includes/specialpage/SpecialPage.php(569): FormSpecialPage->execute(NULL)

#8 /var/www/w/includes/specialpage/SpecialPageFactory.php(558): SpecialPage->run(NULL)

#9 /var/www/w/includes/MediaWiki.php(288): MediaWiki\Special\SpecialPageFactory->executePath(Title, RequestContext)

#10 /var/www/w/includes/MediaWiki.php(865): MediaWiki->performRequest()

#11 /var/www/w/includes/MediaWiki.php(515): MediaWiki->main()

#12 /var/www/w/index.php(42): MediaWiki->run()

#13 {main}

Solved!

It was enough to add the following line in LocalSettings.php

// Add just one user name to the default array

$wgReservedUsernames[] = 'Anonymous';

to get this:

Merge from Giada (691) to Anonymous (0) is complete.

Giada (691) has been deleted.

Thanks to Brian Wolff