Since this package does not work since a Rails 3 were introduced into F15, I am proposing to drop this package from Fedora. It doesn't look anybody will miss it, since nobody reported any issue yet.
rubygem-activeldap was updated to 3.2.2 on rawhide, F-18 one is now f18-updates-pending. https://admin.fedoraproject.org/updates/FEDORA-2012-17508/rubygem-activeldap-3.2.2-1.fc18 Note that rubygem-activeldap deps is still broken on F-17, however I cannot upgrade rubygem-activeldap on F-17 because F-17's rails version is too low. Once closing. Thank you for reporting.