Breaking: #67027 - Removed FLOW-compatibility from PackageManager

See Issue #67027

Description

The Package Manager has been simplified and trimmed down to fit the needs of the TYPO3 extensions and typical Composer packages. All shipped code backported from Flow was removed or refactored to be included in the TYPO3 Core natively. Loading classes are done with the Composer class loader or by the conventions of extension namings. All default Composer packages can still be included as usual, however the custom Flow-logic has been removed.

Impact

It is not possible to add custom Package.php loaders into TYPO3 extensions anymore to be called during runtime. It is not possible to configure extensions with custom Classes/ directories and custom composer.json locations anymore. There is no special handling for “typo3-flow” packages anymore. The typo3conf/PackageStates.php file now only contains the parts that are necessary for the TYPO3 system.

Affected Installations

All installations using custom functionality of the PackageManager not in use with the TYPO3 Core, or installations trying to use Flow packages natively in the TYPO3 Core.

Migration

Use Composer packages natively for class loading, or use ext_localconf.php to additionally configure a package.