Upgrading from 8.3.x to 8.4.0

Running into this:

[2023-09-12 10:03:27] upgrade.INFO: Running step: clear-symfony-cache [] []
[2023-09-12 10:03:27] upgrade.INFO: step: clear-symfony-cache | status: done [] []
[2023-09-12 10:03:27] upgrade.INFO: step: clear-symfony-cache | messages: [] []
[2023-09-12 10:03:27] upgrade.INFO: Successfully cleared cache [] []
[2023-09-12 10:03:27] upgrade.INFO: step: clear-symfony-cache | debug: no debug info [] []
[2023-09-12 10:04:14] upgrade.INFO: Running step: legacy-post-upgrade [] []
Tue, 12 Sep 2023 10:04:14 +0200 [UpgradeWizard] - begin check default permissions .
Tue, 12 Sep 2023 10:04:14 +0200 [UpgradeWizard] - end check default permissions .
Tue, 12 Sep 2023 10:04:14 +0200 [UpgradeWizard] - begin check logger settings .
Tue, 12 Sep 2023 10:04:14 +0200 [UpgradeWizard] - begin check logger settings .
Tue, 12 Sep 2023 10:04:14 +0200 [UpgradeWizard] - begin check lead conversion settings .
Tue, 12 Sep 2023 10:04:14 +0200 [UpgradeWizard] - end check lead conversion settings .
Tue, 12 Sep 2023 10:04:14 +0200 [UpgradeWizard] - begin check resource settings .
Tue, 12 Sep 2023 10:04:14 +0200 [UpgradeWizard] - begin check resource settings .
Tue, 12 Sep 2023 10:04:14 +0200 [UpgradeWizard] - Call deleteCache
[2023-09-12 10:04:14] upgrade.INFO: step: legacy-post-upgrade | status: failed [] []
[2023-09-12 10:04:14] upgrade.INFO: step: legacy-post-upgrade | messages: [] []
[2023-09-12 10:04:14] upgrade.INFO: Unexpected error running Legacy Post Upgrade [] [

I see this PHP error:

Sep 12 08:15:19 crm php: PHP Fatal error:  Cannot declare interface Psr\Container\ContainerInterface, because the name is already in use in /var/www/suitecrm/public_html/vendor/psr/container/src/ContainerInterface.php on line 10

What’s strange is that I can successfully run 8.4.0 from a fresh installation. But I really do want to migrate this 8.3.x data over to the new version.

Strangely enough, if I remove the PHP PSR package, this goes away … :thinking: