Issue #540008 by kristiaanvandeneynde, Spokje, daffie, clayfreeman, alexpott, eelkeblok, michaelfavia, ianthomas_uk, zaporylie, johnwebdev, abhisekmazumdar, anmolgoyal74, greggles, quietone, shaal, catch, rivimey, AaronMcHale, Berdir, ndf, xjm, finne, Wim Leers, esolitos, heddn, webchick, Bojhan, andypost, efpapado, benjifisher, lauriii, Gábor Hojtsy, moshe weitzman, harings_rob: Add a container parameter that can remove the special behavior of UID#1

Issue #3437162 by plopesc, smustgrave, Berdir: Move twig_debug and other development toggles into raw key/value

Issue #2575105 by Berdir, catch, longwave, quietone, kristiaanvandeneynde, andypost, alexpott, mathilde_dumond, pradhumanjain2311, amateescu, Wim Leers, xjm: Use cache collector for state

Issue #2909185 by longwave, donquixote, andypost, andregp, pounard, jibran, martin107, kostyashupenko, catch, znerol: Replace ContainerAwareEventDispatcher with Symfony EventDispatcher

Issue #3436255 by mondrake, longwave: Fix return typehinting for Compiler and EventSubscriber related classes

Issue #2366129 by andypost, stefan.r, smustgrave, vacho: RegisterStreamWrappersPass and other have broken compiler pass for multiple tags

Issue #3415940 by longwave, kristiaanvandeneynde, Spokje: Convert CacheTagsInvalidator to use a service collector

Issue #3412556 by catch, smustgrave, andypost, longwave: Allow needs_destruction services to run on page cache hits

Issue #3394680 followup by longwave: Deprecate ContextProvidersPass in favor of using service_id_collector

Issue #3412168 by godotislate, catch, smustgrave, longwave: Add back "final" to Drupal\big_pipe\StackMiddleware\ContentLength

Issue #2507237 by dimitriskr, twistor, longwave, smustgrave: Replace ReflectionClass::implementsInterface() with is_subclass_of()

Issue #3219667 by quietone, ravi.shankar, longwave, smustgrave: Fix spelling for words used once, beginning with 't' -> 'z', inclusive

Issue #3338328 by Spokje, andypost, longwave, effulgentsia, jungle, catch, smustgrave, Wim Leers: Update to Symfony 6.3

Issue #3278493 by mglaman, rabbitlair, mherchel, Purencool, dww, benjifisher, lauriii, andy-blum, AdamPS, jwilson3, alexpott, smustgrave, rlahoda, akalata, ckrina, bnjmnm, crasx, mndonx, hbrokmeier, callinmullaney: Make it easier for theme builders to enable Twig debugging and disable render cache

(cherry picked from commit da2eaec5)

Issue #3268818 by ravi.shankar, quietone: Fix class comment doc blocks in non tests 'Drupal.Commenting.DocComment.ShortSingleLine'

Issue #2514582 by Mile23, joachim, sahil.goyal, jhodgdon, Fabianx, dawehner: Document lazy services and fix script doxygen

Issue #3032078 by jrglasgow, dagomar, Berdir, nikitagupta, catch, anmolgoyal74, technoveltyco, idebr, ndf, jonas139, nod_: Multiple webheads can cause infinite growth of Twig cache

Issue #2531564 by neclimdul, andypost, chx, cburschka, Spokje, pdenooijer, Charlie ChX Negyesi, znerol, dawehner, longwave, Fabianx, geek-merlin, catch, alexpott: Fix leaky and brittle container serialization solution

Issue #3258902 by longwave, Spokje, catch, daffie: [Symfony 6] Bring stackphp/builder into core for Symfony 6 compatibility and remove it as a dependency

Issue #3197482 by longwave, Spokje, Taran2L, murilohp, catch, Gábor Hojtsy, daffie: Update Drupal 10 to depend on Symfony 5.4 (as a stepping stone to Symfony 6, for deprecation checking support)

Issue #3222251 by bbrala, longwave: [November 8, 2021] Replace all isset constructs with the null coalescing operator

Issue #3231393 by catch, daffie, longwave: [Symfony 6] Symfony\Component\DependencyInjection\Alias::getDeprecationMessage() and Symfony\Component\DependencyInjection\Definition::getDeprecationMessage() method is deprecated, use getDeprecation()

Issue #3018091 by guilhermevp, vacho, shubhangi1995, joachim, longwave, wolffereast: TaggedHandlersPass::process() doesn't document some of its features

Issue #3215397 by dpi, dhirendra.mishra, longwave: Service tag priority does not work with HTTP Client Middleware

Issue #3183036 by claudiu.cristea, jibran, Berdir: Don't instantiate access checkers not used by any route

Issue #3215611 by alexpott, longwave: Service deprecations are only triggered on container build,not ::get()

Issue #3156542 by alexpott, voleger, andypost, Charlie ChX Negyesi, Gábor Hojtsy, longwave: \ReflectionParameter::getClass() is deprecated in PHP 8.0

Issue #3055193 by catch, martin107, jungle, mikelutz, longwave, andypost, alexpott, mondrake, tim.plunkett, larowlan: [Symfony 5] The "Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesser" class is deprecated since Symfony 4.3, use "Symfony\Component\Mime\MimeTypes" instead