MacPorts 2.10.0 broken after Sonoma update 14.6.1 (M2 Max)

After migrating to MacPorts 2.10.0 via

$ sudo port selfupdating
Password:
--->  Updating MacPorts base sources using rsync
MacPorts base version 2.9.3 installed,
MacPorts base version 2.10.0 downloaded.
--->  Updating the ports tree
--->  MacPorts base is outdated, installing new version 2.10.0
Installing new MacPorts release in /opt/local as root:wheel; permissions 0775

Error: Error installing new MacPorts base: command execution failed
Please run `port -v selfupdate' for details.
Error: /opt/local/bin/port: port selfupdate failed: Error installing new MacPorts base: command execution failed

I tried sudo port migrate together with the recommended change to the new URL in sources.conf. A following selfupdate produced the output

$ sudo port selfupdate
--->  Checking for newer releases of MacPorts
MacPorts base version 2.10.0 installed,
MacPorts base version 2.10.0 available.
--->  MacPorts base is already the latest version
--->  Updating the ports tree
Error: updating PortIndex for rsync://rsync.macports.org/macports/release/tarballs/ports.tar failed

The ports tree has been updated.

29 ports are outdated. Run 'port outdated' for details.
To upgrade your installed ports, you should run
  port upgrade outdated

Unfortunately, it seems that now MacPorts is broken:

$ sudo port outdated
Error: Current platform "darwin 23" does not match expected platform "darwin 23"
Error: Please run 'sudo port migrate' or follow the migration instructions: https://trac.macports.org/wiki/Migration 
OS platform mismatch
    while executing
"mportinit ui_options global_options global_variations"
Error: /opt/local/bin/port: Failed to initialize MacPorts, OS platform mismatch

Any help is highly appreciated.