MediaWiki requires Composer 2 and will not work with Composer 1 any
more. I have ran into the same issue myself
(
https://github.com/MatmaRex/patchdemo/issues/501).
It's not clear to me whether this is a bug or an intentional
compatibility break. Looks like
https://phabricator.wikimedia.org/T316556 is a bug report about this,
but it's also connected to a task about dropping compatibility, so I
wouldn't hold my breath waiting for it to be fixed.
You will need to either:
* Upgrade your Ubuntu to a version that ships with Composer 2 – looking
at
https://packages.ubuntu.com/search?keywords=composer , that would be
Ubuntu 22.04 Jammy.
* Or install Composer 2 manually instead of from the system repositories
–
https://getcomposer.org/download/
--
Bartosz Dziewoński