Updating with latest changes that support Ubuntu 22.04 as well.
If I downgrade to PHP 8.1 the "require dev" trick works. However I run into a Symfony problem which I believe Steven Jones has a solution for -- awaiting his next blog post!
@SocialNicheGuru This is with Aegir 3 installed via our Ansible playbook from head on the 7.x-3.x branch, with PHP 8.2. With @steven-jones's fix for 🐛 Default value of field is incorrect Fixed , I'm able to create and verify a D10 platform. However I can't install a site due to drush 12's enforced promiscuity, as @colan's "require-dev" trick from 🐛 Aegir 3 is incompatible with Drush 9+ Active no longer appears to work. If I find a way to get past that (or if Steven Jones does, as that seems to be his goal), then maybe this issue can be resolved by either the symlink trick I described above or by copying the contents of packages_9.inc holus bolus into a new packages_10.inc.
In validating @steven-jones's recent work on https://www.drupal.org/project/hosting_deploy/issues/3420075 🐛 Default value of field is incorrect Fixed , we found that all we had to do was symlink `/var/aegir/.drush/provision/platform/drupal/packages_10.inc` to `/var/aegir/.drush/provision/platform/drupal/packages_9.inc` -- presumably that's not the correct long term solution, but with that, I was able to verify a D10 platform.