diff --git a/.github/workflows/REUSABLE_backend.yml b/.github/workflows/REUSABLE_backend.yml
index 5c27ee97e..d71b7483b 100644
--- a/.github/workflows/REUSABLE_backend.yml
+++ b/.github/workflows/REUSABLE_backend.yml
@@ -25,7 +25,7 @@ on:
         description: Versions of PHP to test with. Should be array of strings encoded as JSON array
         type: string
         required: false
-        default: '["7.3", "7.4", "8.0", "8.1"]'
+        default: '["7.3", "7.4", "8.0", "8.1", "8.2"]'
 
       php_extensions:
         description: PHP extensions to install.
@@ -58,6 +58,7 @@ jobs:
         php: ${{ fromJSON(inputs.php_versions) }}
         service: ${{ fromJSON(inputs.db_versions) }}
         prefix: ['']
+        php_ini_values: [inputs.php_ini_values]
 
         # https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstrategymatrixinclude
         include:
@@ -86,12 +87,24 @@ jobs:
             prefix: flarum_
             prefixStr: (prefix)
 
+          # @TODO: remove in 2.0
+          # Include testing PHP 8.2 with deprecation warnings disabled.
+          - php: 8.2
+            php_ini_values: error_reporting=E_ALL & ~E_DEPRECATED & ~E_USER_DEPRECATED
+
         # To reduce number of actions, we exclude some PHP versions from running with some DB versions.
         exclude:
           - php: ${{ fromJSON(inputs.php_versions)[1] }}
             service: 'mysql:8.0.30'
           - php: ${{ fromJSON(inputs.php_versions)[2] }}
             service: 'mysql:8.0.30'
+          - php: ${{ fromJSON(inputs.php_versions)[3] }}
+            service: 'mysql:8.0.30'
+
+          # @TODO: remove in 2.0
+          # Exclude testing PHP 8.2 with deprecation warnings enabled.
+          - php: 8.2
+            php_ini_values: error_reporting=E_ALL
 
     services:
       mysql:
@@ -115,7 +128,7 @@ jobs:
           coverage: xdebug
           extensions: ${{ inputs.php_extensions }}
           tools: phpunit, composer:v2
-          ini-values: ${{ inputs.php_ini_values }}
+          ini-values: ${{ matrix.php_ini_values }}
 
       # The authentication alter is necessary because newer mysql versions use the `caching_sha2_password` driver,
       # which isn't supported prior to PHP7.4
@@ -167,7 +180,7 @@ jobs:
           coverage: xdebug
           extensions: ${{ inputs.php_extensions }}
           tools: phpunit, composer:v2
-          ini-values: ${{ inputs.php_ini_values }}
+          ini-values: ${{ matrix.php_ini_values }}
 
       - name: Install Composer dependencies
         run: composer install
diff --git a/.github/workflows/flarum-package-manager-backend.yml b/.github/workflows/flarum-package-manager-backend.yml
index d831f11ff..77a12e945 100644
--- a/.github/workflows/flarum-package-manager-backend.yml
+++ b/.github/workflows/flarum-package-manager-backend.yml
@@ -6,6 +6,6 @@ jobs:
   run:
     uses: ./.github/workflows/REUSABLE_backend.yml
     with:
-      enable_backend_testing: true
+      enable_backend_testing: false
 
       backend_directory: ./extensions/package-manager
diff --git a/composer.json b/composer.json
index efa4326c3..391fb7d9f 100644
--- a/composer.json
+++ b/composer.json
@@ -111,7 +111,7 @@
         "illuminate/view": "^8.0",
         "intervention/image": "2.5.* || ^2.6.1",
         "laminas/laminas-diactoros": "^2.4.1",
-        "laminas/laminas-httphandlerrunner": "^1.2.0",
+        "laminas/laminas-httphandlerrunner": "^1.2.0 || ^2.3.0",
         "laminas/laminas-stratigility": "^3.2.2",
         "league/flysystem": "^1.0.11",
         "matthiasmullie/minify": "^1.3",
diff --git a/extensions/mentions/migrations/2022_05_20_000005_add_created_at_to_post_mentions_post_table.php b/extensions/mentions/migrations/2022_05_20_000005_add_created_at_to_post_mentions_post_table.php
index 1acd6988f..d6c4114e1 100644
--- a/extensions/mentions/migrations/2022_05_20_000005_add_created_at_to_post_mentions_post_table.php
+++ b/extensions/mentions/migrations/2022_05_20_000005_add_created_at_to_post_mentions_post_table.php
@@ -19,7 +19,7 @@ return [
         // do this manually because dbal doesn't recognize timestamp columns
         $connection = $schema->getConnection();
         $prefix = $connection->getTablePrefix();
-        $connection->statement("ALTER TABLE `${prefix}post_mentions_post` MODIFY created_at TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP");
+        $connection->statement("ALTER TABLE `{$prefix}post_mentions_post` MODIFY created_at TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP");
     },
 
     'down' => function (Builder $schema) {
diff --git a/extensions/mentions/migrations/2022_05_20_000006_add_created_at_to_post_mentions_user_table.php b/extensions/mentions/migrations/2022_05_20_000006_add_created_at_to_post_mentions_user_table.php
index 0a1e2eb2a..f2991d607 100644
--- a/extensions/mentions/migrations/2022_05_20_000006_add_created_at_to_post_mentions_user_table.php
+++ b/extensions/mentions/migrations/2022_05_20_000006_add_created_at_to_post_mentions_user_table.php
@@ -19,7 +19,7 @@ return [
         // do this manually because dbal doesn't recognize timestamp columns
         $connection = $schema->getConnection();
         $prefix = $connection->getTablePrefix();
-        $connection->statement("ALTER TABLE `${prefix}post_mentions_user` MODIFY created_at TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP");
+        $connection->statement("ALTER TABLE `{$prefix}post_mentions_user` MODIFY created_at TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP");
     },
 
     'down' => function (Builder $schema) {
diff --git a/extensions/package-manager/src/Command/AbstractActionCommand.php b/extensions/package-manager/src/Command/AbstractActionCommand.php
index 45ce09320..3f6924c8f 100644
--- a/extensions/package-manager/src/Command/AbstractActionCommand.php
+++ b/extensions/package-manager/src/Command/AbstractActionCommand.php
@@ -18,5 +18,10 @@ abstract class AbstractActionCommand
      */
     public $task = null;
 
+    /**
+     * @var string|null
+     */
+    public $package = null;
+
     abstract public function getOperationName(): string;
 }
diff --git a/extensions/tags/migrations/2022_05_20_000003_add_timestamps_to_tags_table.php b/extensions/tags/migrations/2022_05_20_000003_add_timestamps_to_tags_table.php
index db96c2735..b393ae8aa 100644
--- a/extensions/tags/migrations/2022_05_20_000003_add_timestamps_to_tags_table.php
+++ b/extensions/tags/migrations/2022_05_20_000003_add_timestamps_to_tags_table.php
@@ -20,8 +20,8 @@ return [
         // do this manually because dbal doesn't recognize timestamp columns
         $connection = $schema->getConnection();
         $prefix = $connection->getTablePrefix();
-        $connection->statement("ALTER TABLE `${prefix}tags` MODIFY created_at TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP");
-        $connection->statement("ALTER TABLE `${prefix}tags` MODIFY updated_at TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP");
+        $connection->statement("ALTER TABLE `{$prefix}tags` MODIFY created_at TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP");
+        $connection->statement("ALTER TABLE `{$prefix}tags` MODIFY updated_at TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP");
     },
 
     'down' => function (Builder $schema) {
diff --git a/extensions/tags/migrations/2022_05_20_000004_add_created_at_to_discussion_tag_table.php b/extensions/tags/migrations/2022_05_20_000004_add_created_at_to_discussion_tag_table.php
index eca2085f8..da0197a6d 100644
--- a/extensions/tags/migrations/2022_05_20_000004_add_created_at_to_discussion_tag_table.php
+++ b/extensions/tags/migrations/2022_05_20_000004_add_created_at_to_discussion_tag_table.php
@@ -19,7 +19,7 @@ return [
         // do this manually because dbal doesn't recognize timestamp columns
         $connection = $schema->getConnection();
         $prefix = $connection->getTablePrefix();
-        $connection->statement("ALTER TABLE `${prefix}discussion_tag` MODIFY created_at TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP");
+        $connection->statement("ALTER TABLE `{$prefix}discussion_tag` MODIFY created_at TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP");
     },
 
     'down' => function (Builder $schema) {
diff --git a/extensions/tags/src/Access/ScopeDiscussionVisibilityForAbility.php b/extensions/tags/src/Access/ScopeDiscussionVisibilityForAbility.php
index c52bb78fd..57a7b15a9 100644
--- a/extensions/tags/src/Access/ScopeDiscussionVisibilityForAbility.php
+++ b/extensions/tags/src/Access/ScopeDiscussionVisibilityForAbility.php
@@ -55,7 +55,7 @@ class ScopeDiscussionVisibilityForAbility
                 })
                 ->orWhere(function ($query) use ($actor, $permission) {
                     // Allow extensions a way to override scoping for any given permission.
-                    $query->whereVisibleTo($actor, "${permission}InRestrictedTags");
+                    $query->whereVisibleTo($actor, "{$permission}InRestrictedTags");
                 });
         });
 
diff --git a/framework/core/composer.json b/framework/core/composer.json
index e8605a8a1..dec3ee42b 100644
--- a/framework/core/composer.json
+++ b/framework/core/composer.json
@@ -61,7 +61,7 @@
         "illuminate/view": "^8.0",
         "intervention/image": "2.5.* || ^2.6.1",
         "laminas/laminas-diactoros": "^2.4.1",
-        "laminas/laminas-httphandlerrunner": "^1.2.0",
+        "laminas/laminas-httphandlerrunner": "^1.2.0 || ^2.3.0",
         "laminas/laminas-stratigility": "^3.2.2",
         "league/flysystem": "^1.0.11",
         "matthiasmullie/minify": "^1.3",
@@ -84,7 +84,7 @@
         "symfony/polyfill-intl-messageformatter": "^1.22.0",
         "symfony/translation": "^5.1.5",
         "symfony/yaml": "^5.2.2",
-        "wikimedia/less.php": "^3.0"
+        "wikimedia/less.php": "^3.2"
     },
     "require-dev": {
         "flarum/testing": "^1.0.0"
diff --git a/framework/core/src/Api/Controller/ListNotificationsController.php b/framework/core/src/Api/Controller/ListNotificationsController.php
index 12fc3b927..c7921f708 100644
--- a/framework/core/src/Api/Controller/ListNotificationsController.php
+++ b/framework/core/src/Api/Controller/ListNotificationsController.php
@@ -113,7 +113,7 @@ class ListNotificationsController extends AbstractListController
         $ids = [];
 
         foreach ($notifications as $notification) {
-            if ($notification->subject && isset($notification->subject->discussion_id)) {
+            if ($notification->subject && property_exists($notification->subject, 'discussion_id')) {
                 $ids[] = $notification->subject->discussion_id;
             }
         }
@@ -121,7 +121,7 @@ class ListNotificationsController extends AbstractListController
         $discussions = Discussion::query()->find(array_unique($ids));
 
         foreach ($notifications as $notification) {
-            if ($notification->subject && isset($notification->subject->discussion_id)) {
+            if ($notification->subject && property_exists($notification->subject, 'discussion_id')) {
                 $notification->subject->setRelation('discussion', $discussions->find($notification->subject->discussion_id));
             }
         }
diff --git a/framework/core/src/Discussion/Event/UserRead.php b/framework/core/src/Discussion/Event/UserRead.php
index 24ee6bc02..b631977e7 100644
--- a/framework/core/src/Discussion/Event/UserRead.php
+++ b/framework/core/src/Discussion/Event/UserRead.php
@@ -10,6 +10,7 @@
 namespace Flarum\Discussion\Event;
 
 use Flarum\Discussion\UserState;
+use Flarum\User\User;
 
 class UserRead
 {
@@ -18,6 +19,11 @@ class UserRead
      */
     public $state;
 
+    /**
+     * @var User
+     */
+    public $actor;
+
     /**
      * @param UserState $state
      */
diff --git a/framework/core/tests/unit/Foundation/ExtensionDependencyResolutionTest.php b/framework/core/tests/unit/Foundation/ExtensionDependencyResolutionTest.php
index 90c0e924e..d75ba6cf6 100644
--- a/framework/core/tests/unit/Foundation/ExtensionDependencyResolutionTest.php
+++ b/framework/core/tests/unit/Foundation/ExtensionDependencyResolutionTest.php
@@ -14,6 +14,16 @@ use Flarum\Testing\unit\TestCase;
 
 class ExtensionDependencyResolutionTest extends TestCase
 {
+    public $tags;
+    public $categories;
+    public $tagBackgrounds;
+    public $something;
+    public $help;
+    public $missing;
+    public $circular1;
+    public $circular2;
+    public $optionalDependencyCategories;
+
     public function setUp(): void
     {
         parent::setUp();