Fri. 1st April, 2011
All version 4 core issues are now handled at forge.typo3.org/projects/typo3v4-core/issues. Handling all issues at forge makes it easier for developers and reporters, as all core relevant bug trackers are now in one place.
This is a companion discussion topic for the original entry at https://typo3.org/article/migration-from-mantis-to-forge-1/