It seems that you cannot log in to the OPAC with the new patron clubs feature. Logging in when no clubs are defined gives: The method get_club_enrollments_count is not covered by tests! at /home/vagrant/kohaclone/C4/Templates.pm line 121. If you have clubs defined, logging in gives you: Template process failed: undef error - The method size is not covered by tests! at /home/vagrant/kohaclone/C4/Templates.pm line 121. Reverting the patch for the clubs resolves this issue.
Changed to critical for the bug it blocks, but it isn't a blocker in Koha.
Bug 12461 has been reverted.