feat(scopes): remove Hub and related classes

UPGRADE-5.0.md

@@ -21,6 +21,39 @@ $logger->pushHandler(new \Sentry\Monolog\LogsHandler());
 
 To continue sending Monolog records to Sentry issues instead, use `Sentry\Monolog\LogToSentryIssueHandler` for log messages or `Sentry\Monolog\ExceptionToSentryIssueHandler` for exceptions.
 
+### Hub APIs Removed
+
+The Hub API has been removed. This includes:
+
+- **Removed classes and interfaces:**
+  - `Sentry\State\Hub`
+  - `Sentry\State\HubAdapter`
+  - `Sentry\State\HubInterface`
+
+- **Removed methods:**
+  - `SentrySdk::getCurrentHub()`
+  - `SentrySdk::setCurrentHub()`
+
+The SDK now exposes runtime state directly through `SentrySdk`, global helpers, and `Scope`:
+
+```php
+// Before (4.x)
+\Sentry\SentrySdk::getCurrentHub()->configureScope(static function (\Sentry\State\Scope $scope): void {
+    $scope->setTag('feature', 'checkout');
+});
+
+// After (5.0)
+\Sentry\configureScope(static function (\Sentry\State\Scope $scope): void {
+    $scope->setTag('feature', 'checkout');
+});
+```
+
+Use `SentrySdk::getClient()` for the active client, `SentrySdk::getGlobalScope()` for process-global data, and `SentrySdk::getIsolationScope()` for the current runtime isolation scope. Use the capture helpers such as `captureMessage()`, `captureException()`, and `captureEvent()` to send events.
+
+Use `configureScope()` to mutate the current isolation scope, `withIsolationScope()` to run code with a temporary forked scope, and `startTransaction()` to start manual tracing instrumentation.
+
+`SentrySdk::init()` no longer returns a Hub instance. It now returns `void`.
+
 ### Metrics API Removed
 
 The entire Metrics API has been removed as it is no longer supported. This includes:

analysis-baseline.toml

@@ -1368,18 +1368,6 @@ code = "possibly-invalid-argument"
 message = '''Possible argument type mismatch for argument #1 of `Sentry\StacktraceBuilder::buildFromBacktrace`: expected `list<array{'args'?: array<array-key, mixed>, 'class'?: class-string, 'file'?: string, 'function'?: string, 'line'?: int, 'type'?: string}>`, but possibly received `array<array-key, mixed>`.'''
 count = 1
 
-[[issues]]
-file = "src/State/Hub.php"
-code = "mixed-operand"
-message = "Right operand in `<` comparison has `mixed` type."
-count = 1
-
-[[issues]]
-file = "src/State/Hub.php"
-code = "possibly-null-operand"
-message = "Left operand in `<` comparison might be `null` (type `float|null`)."
-count = 1
-
 [[issues]]
 file = "src/State/Scope.php"
 code = "impossible-condition"

src/Integration/ModulesIntegration.php

@@ -28,8 +28,6 @@ public function setupOnce(): void
         Scope::addGlobalEventProcessor(static function (Event $event): Event {
             $integration = SentrySdk::getClient()->getIntegration(self::class);
 
-            // The integration could be bound to a client that is not the one
-            // attached to the current hub. If this is the case, bail out
             if ($integration !== null) {
                 $event->setModules(self::getComposerPackages());
             }

src/Integration/TransactionIntegration.php

@@ -26,8 +26,6 @@ public function setupOnce(): void
         Scope::addGlobalEventProcessor(static function (Event $event, EventHint $hint): Event {
             $integration = SentrySdk::getClient()->getIntegration(self::class);
 
-            // The client bound to the current hub, if any, could not have this
-            // integration enabled. If this is the case, bail out
             if ($integration === null) {
                 return $event;
             }

src/SentrySdk.php

@@ -6,8 +6,6 @@
 
 use Sentry\Logs\Logs;
 use Sentry\Metrics\TraceMetrics;
-use Sentry\State\HubAdapter;
-use Sentry\State\HubInterface;
 use Sentry\State\RuntimeContext;
 use Sentry\State\RuntimeContextManager;
 use Sentry\State\Scope;
@@ -37,38 +35,15 @@ private function __construct()
     }
 
     /**
-     * Initializes the SDK by binding the client to the global scope and reset
+     * Initializes the SDK by binding the client to the global scope and resetting
      * the current local runtime state.
      */
-    public static function init(?ClientInterface $client = null): HubInterface
+    public static function init(?ClientInterface $client = null): void
     {
         if ($client !== null) {
             self::getGlobalScope()->setClient($client);
         }
         self::$runtimeContextManager = new RuntimeContextManager();
-
-        return self::getCurrentHub();
-    }
-
-    public static function getCurrentHub(): HubInterface
-    {
-        return HubAdapter::getInstance();
-    }
-
-    /**
-     * Sets the current hub.
-     *
-     * If called while an explicit runtime context is active, the hub update is
-     * scoped to that active context only. Otherwise, it updates the baseline
-     * hub used by the global fallback context and future contexts.
-     *
-     * @param HubInterface $hub The hub to set
-     */
-    public static function setCurrentHub(HubInterface $hub): HubInterface
-    {
-        self::getGlobalScope()->setClient($hub->getClient());
-
-        return $hub;
     }
 
     public static function getGlobalScope(): Scope