- New upstream release of 0.5.6.
    - Show a message to the user if the repo could not be reached. Fixes
        #531838
    - Include PackageKit in the list of essential packages.
    - Fix a crash where the extra library check file callbacks had the wrong
        signature.
    - Correct the transaction RequireRestart extra callback to fix a potential
        crash.
    - Ensure to set the correct error if getting the transaction ID fails.
        Fixes #551546
    - Ensure we send error messages to stderr, not stdout. Fixes #545220