fix(ios): preload Cocoa crash handlers for managed runtime interop

- Build sentry-cocoa with SENTRY_CRASH_MANAGED_RUNTIME to preload signal
  handlers and exclude EXC_BAD_ACCESS/EXC_ARITHMETIC from Mach monitoring
- Call PrivateSentrySDKOnly.IgnoreNextSignal(SIGABRT) from
  MarshalManagedException to prevent duplicate native crash events
- Update iOS integration tests to expect no duplicate events (#3954)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: jpnurmi

integration-test/ios.Tests.ps1

@@ -99,9 +99,8 @@ Describe 'iOS app (<tfm>, <configuration>)' -ForEach @(
 
         $result.HasErrors() | Should -BeFalse
         $result.Envelopes() | Should -AnyElementMatch "`"type`":`"System.ApplicationException`""
-        # TODO: fix redundant SIGABRT (#3954)
-        { $result.Envelopes() | Should -Not -AnyElementMatch "`"type`":`"SIGABRT`"" } | Should -Throw
-        { $result.Envelopes() | Should -HaveCount 1 } | Should -Throw
+        $result.Envelopes() | Should -Not -AnyElementMatch "`"type`":`"(EXC_[A-Z_]+|SIG[A-Z]+)`""
+        $result.Envelopes() | Should -HaveCount 1
     }
 
     It 'captures native crash (<configuration>)' {
@@ -112,7 +111,7 @@ Describe 'iOS app (<tfm>, <configuration>)' -ForEach @(
         }
 
         $result.HasErrors() | Should -BeFalse
-        $result.Envelopes() | Should -AnyElementMatch "`"type`":`"EXC_[A-Z_]+`""
+        $result.Envelopes() | Should -AnyElementMatch "`"type`":`"(EXC_[A-Z_]+|SIG[A-Z]+)`""
         $result.Envelopes() | Should -Not -AnyElementMatch "`"type`":`"System.\w+Exception`""
         $result.Envelopes() | Should -HaveCount 1
     }
@@ -126,12 +125,7 @@ Describe 'iOS app (<tfm>, <configuration>)' -ForEach @(
 
         $result.HasErrors() | Should -BeFalse
         $result.Envelopes() | Should -AnyElementMatch "`"type`":`"System.NullReferenceException`""
-        # TODO: fix redundant EXC_BAD_ACCESS in Release (#3954)
-        if ($configuration -eq 'Release') {
-            { $result.Envelopes() | Should -Not -AnyElementMatch "`"type`":`"EXC_BAD_ACCESS`"" } | Should -Throw
-        } else {
-            $result.Envelopes() | Should -Not -AnyElementMatch "`"type`":`"EXC_BAD_ACCESS`""
-            $result.Envelopes() | Should -HaveCount 1
-        }
+        $result.Envelopes() | Should -Not -AnyElementMatch "`"type`":`"(EXC_[A-Z_]+|SIG[A-Z]+)`""
+        $result.Envelopes() | Should -HaveCount 1
     }
 }

scripts/build-sentry-cocoa.sh

@@ -50,15 +50,17 @@ xcodebuild archive -project Sentry.xcodeproj \
     -sdk "$ios_sdk" \
     -archivePath ./Carthage/output-ios.xcarchive \
     SKIP_INSTALL=NO \
-    BUILD_LIBRARY_FOR_DISTRIBUTION=YES
+    BUILD_LIBRARY_FOR_DISTRIBUTION=YES \
+    GCC_PREPROCESSOR_DEFINITIONS='$(inherited) SENTRY_CRASH_MANAGED_RUNTIME=1'
 ./scripts/remove-architectures.sh ./Carthage/output-ios.xcarchive arm64e
 xcodebuild archive -project Sentry.xcodeproj \
     -scheme Sentry \
     -configuration Release \
     -sdk "$ios_simulator_sdk" \
     -archivePath ./Carthage/output-iossimulator.xcarchive \
     SKIP_INSTALL=NO \
-    BUILD_LIBRARY_FOR_DISTRIBUTION=YES
+    BUILD_LIBRARY_FOR_DISTRIBUTION=YES \
+    GCC_PREPROCESSOR_DEFINITIONS='$(inherited) SENTRY_CRASH_MANAGED_RUNTIME=1'
 xcodebuild -create-xcframework \
     -framework ./Carthage/output-ios.xcarchive/Products/Library/Frameworks/Sentry.framework \
     -framework ./Carthage/output-iossimulator.xcarchive/Products/Library/Frameworks/Sentry.framework \
@@ -73,7 +75,8 @@ xcodebuild archive -project Sentry.xcodeproj \
     -destination 'generic/platform=macOS,variant=Mac Catalyst' \
     -archivePath ./Carthage/output-maccatalyst.xcarchive \
     SKIP_INSTALL=NO \
-    BUILD_LIBRARY_FOR_DISTRIBUTION=YES
+    BUILD_LIBRARY_FOR_DISTRIBUTION=YES \
+    GCC_PREPROCESSOR_DEFINITIONS='$(inherited) SENTRY_CRASH_MANAGED_RUNTIME=1'
 ./scripts/remove-architectures.sh ./Carthage/output-maccatalyst.xcarchive arm64e
 xcodebuild -create-xcframework \
     -framework ./Carthage/output-maccatalyst.xcarchive/Products/Library/Frameworks/Sentry.framework \

src/Sentry/Platforms/Cocoa/RuntimeMarshalManagedExceptionIntegration.cs

@@ -43,6 +43,12 @@ internal void Handle(object sender, MarshalManagedExceptionEventArgs e)
 
             // This is likely a terminal exception so try to send the crash report before shutting down
             _hub?.Flush();
+
+            // The Xamarin runtime will call abort() after this handler returns, which raises
+            // SIGABRT. Tell SentryCrash to ignore it on this thread so we don't get a duplicate
+            // native crash event for a managed exception we've already captured.
+            const int SIGABRT = 6;
+            SentryCocoaHybridSdk.IgnoreNextSignal(SIGABRT);
         }
     }
 }