Steps to replicate the issue (include links if applicable):

Run rebuildFileCache.php from MM 1.38.4 tarball.

What happens?:

Many warnings like:

PHP Deprecated: Premature access to service container [Called from RebuildFileCache::finalSetup in /var/www/html/w/maintenance/rebuildFileCache.php at line 54] in /var/www/html/w/includes/debug/MWDebug.php on line 377

What should have happened instead?:

The maintenance script should be clean.

Software version (skip for WMF-hosted wikis like Wikipedia):

MW 1.38.4

Other information (browser name/version, screenshots, etc.):

Ubuntu 20.04, x86_64, fully patched
PHP 7.4.3

PHP Deprecated: Premature access to service container [Called from RebuildFileCache::finalSetup in /var/www/html/w/maintenance/rebuildFileCache.php at line 54] in /var/www/html/w/includes/debug/MWDebug.php on line 377

Deprecated: Premature access to service container [Called from RebuildFileCache::finalSetup in /var/www/html/w/maintenance/rebuildFileCache.php at line 54] in /var/www/html/w/includes/debug/MWDebug.php on line 377
PHP Deprecated: Premature access to service 'HookContainer' [Called from MediaWiki\MediaWikiServices::getInstance in /var/www/html/w/includes/MediaWikiServices.php at line 282] in /var/www/html/w/includes/debug/MWDebug.php on line 377

Deprecated: Premature access to service 'HookContainer' [Called from MediaWiki\MediaWikiServices::getInstance in /var/www/html/w/includes/MediaWikiServices.php at line 282] in /var/www/html/w/includes/debug/MWDebug.php on line 377
PHP Deprecated: Premature access to service 'ObjectFactory' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 687] in /var/www/html/w/includes/debug/MWDebug.php on line 377

Deprecated: Premature access to service 'ObjectFactory' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 687] in /var/www/html/w/includes/debug/MWDebug.php on line 377
PHP Deprecated: Premature access to service 'ReadOnlyMode' [Called from RebuildFileCache::finalSetup in /var/www/html/w/maintenance/rebuildFileCache.php at line 54] in /var/www/html/w/includes/debug/MWDebug.php on line 377

Deprecated: Premature access to service 'ReadOnlyMode' [Called from RebuildFileCache::finalSetup in /var/www/html/w/maintenance/rebuildFileCache.php at line 54] in /var/www/html/w/includes/debug/MWDebug.php on line 377
PHP Deprecated: Premature access to service 'ConfiguredReadOnlyMode' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 1362] in /var/www/html/w/includes/debug/MWDebug.php on line 377

Deprecated: Premature access to service 'ConfiguredReadOnlyMode' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 1362] in /var/www/html/w/includes/debug/MWDebug.php on line 377
PHP Deprecated: Premature access to service 'MainConfig' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 406] in /var/www/html/w/includes/debug/MWDebug.php on line 377

Deprecated: Premature access to service 'MainConfig' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 406] in /var/www/html/w/includes/debug/MWDebug.php on line 377
PHP Deprecated: Premature access to service 'ConfigFactory' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 905] in /var/www/html/w/includes/debug/MWDebug.php on line 377

Deprecated: Premature access to service 'ConfigFactory' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 905] in /var/www/html/w/includes/debug/MWDebug.php on line 377
PHP Deprecated: Premature access to service 'BootstrapConfig' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 392] in /var/www/html/w/includes/debug/MWDebug.php on line 377

Deprecated: Premature access to service 'BootstrapConfig' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 392] in /var/www/html/w/includes/debug/MWDebug.php on line 377
PHP Deprecated: Premature access to service 'DBLoadBalancer' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 1363] in /var/www/html/w/includes/debug/MWDebug.php on line 377

Deprecated: Premature access to service 'DBLoadBalancer' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 1363] in /var/www/html/w/includes/debug/MWDebug.php on line 377
PHP Deprecated: Premature access to service 'DBLoadBalancerFactory' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 508] in /var/www/html/w/includes/debug/MWDebug.php on line 377

Deprecated: Premature access to service 'DBLoadBalancerFactory' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 508] in /var/www/html/w/includes/debug/MWDebug.php on line 377
PHP Deprecated: Premature access to service 'StatsdDataFactory' [Called from ObjectCache::newFromParams in /var/www/html/w/includes/objectcache/ObjectCache.php at line 149] in /var/www/html/w/includes/debug/MWDebug.php on line 377

Deprecated: Premature access to service 'StatsdDataFactory' [Called from ObjectCache::newFromParams in /var/www/html/w/includes/objectcache/ObjectCache.php at line 149] in /var/www/html/w/includes/debug/MWDebug.php on line 377
PHP Deprecated: Premature access to service 'LocalServerObjectCache' [Called from ObjectCache::getLocalServerInstance in /var/www/html/w/includes/objectcache/ObjectCache.php at line 256] in /var/www/html/w/includes/debug/MWDebug.php on line 377

Deprecated: Premature access to service 'LocalServerObjectCache' [Called from ObjectCache::getLocalServerInstance in /var/www/html/w/includes/objectcache/ObjectCache.php at line 256] in /var/www/html/w/includes/debug/MWDebug.php on line 377
PHP Deprecated: Premature access to service 'MainWANObjectCache' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 531] in /var/www/html/w/includes/debug/MWDebug.php on line 377

Deprecated: Premature access to service 'MainWANObjectCache' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 531] in /var/www/html/w/includes/debug/MWDebug.php on line 377
PHP Deprecated: Premature access to service 'CriticalSectionProvider' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 549] in /var/www/html/w/includes/debug/MWDebug.php on line 377

Deprecated: Premature access to service 'CriticalSectionProvider' [Called from Wikimedia\Services\ServiceContainer::{closure} in /var/www/html/w/includes/ServiceWiring.php at line 549] in /var/www/html/w/includes/debug/MWDebug.php on line 377