Debug mode and hot reload fail on iOS 26 due to JIT restriction `error: mprotect failed: 13 (Permission denied)`

[passsionforprogramming]

Workarounds

Important

iOS 26 beta 1 breaks Flutter's debug mode on physical devices. If you have upgraded your device to 26 beta 1, please use the simulator until the issue is resolved, or downgrade to iOS 18.x.

Steps to reproduce

1. Run flutter ios in debug mode with ios 18.4
2. Notice the error ../../../flutter/third_party/dart/runtime/vm/virtual_memory_posix.cc: 428: error: mprotect failed: 13 (Permission denied)
3. The build will fail. === Crash occurred when compiling unknown function in unoptimized JIT mode in unknown pass

Expected results

Fluter build should not fail when in debug mode.

Actual results

Flutter build fails on ios in debug mode with version 18.4

Code sample

This is related to the build and not the code.

Screenshots or Video

Screenshots / Video demonstration

[Upload media here]

Logs

Logs

../../../flutter/third_party/dart/runtime/vm/virtual_memory_posix.cc: 428: error: mprotect failed: 13 (Permission denied)
version=3.7.0 (stable) (Wed Feb 5 04:53:58 2025 -0800) on "ios_arm64"
pid=726, thread=259, isolate_group=vm-isolate(0x11ea52800), isolate=vm-isolate(0x11ebe5800)
os=ios, arch=arm64, comp=no, sim=no
isolate_instructions=10f8ab5a0, vm_instructions=10f8ab5a0
fp=16eee4f50, sp=16eee4f30, pc=110302e84
  pc 0x0000000110302e84 fp 0x000000016eee4f50 Dart_DumpNativeStackTrace+0x18
  pc 0x000000010feb1428 fp 0x000000016eee4f70 dart::Assert::Fail(char const*, ...) const+0x30
  pc 0x000000010ffac33c fp 0x000000016eee5420 dart::Code::FinalizeCode(dart::FlowGraphCompiler*, dart::compiler::Assembler*, dart::Code::PoolAttachment, bool, dart::CodeStatistics*)+0x82c
  pc 0x0000000110039cb0 fp 0x000000016eee5a30 dart::StubCode::Init()+0x320
  pc 0x000000010fefc4f4 fp 0x000000016eee64e0 dart::Dart::DartInit(Dart_InitializeParams const*)+0x2b18
  pc 0x00000001102e9754 fp 0x000000016eee6960 Dart_Initialize+0x60
  pc 0x000000010fe71e24 fp 0x000000016eee6f30 flutter::DartVM::Create(flutter::Settings const&, fml::RefPtr<flutter::DartSnapshot const>, fml::RefPtr<flutter::DartSnapshot const>, std::_fl::shared_ptr<flutter::IsolateNameServer>)+0x1d64
  pc 0x000000010fdcdf9c fp 0x000000016eee7690 flutter::Shell::Create(flutter::PlatformData const&, flutter::TaskRunners const&, flutter::Settings, std::_fl::function<std::_fl::unique_ptr<flutter::PlatformView, std::_fl::default_delete<flutter::PlatformView>> (flutter::Shell&)> const&, std::_fl::function<std::_fl::unique_ptr<flutter::Rasterizer, std::_fl::default_delete<flutter::Rasterizer>> (flutter::Shell&)> const&, bool)+0x310
  pc 0x000000010f8ba564 fp 0x000000016eee8420 -[FlutterEngine createShell:libraryURI:initialRoute:]+0xa8c
  pc 0x000000010f8ece64 fp 0x000000016eee8480 -[FlutterViewController sharedSetupWithProject:initialRoute:]+0x198
  pc 0x000000010f8ecca4 fp 0x000000016eee84b0 -[FlutterViewController awakeFromNib]+0x6c
  pc 0x000000018a580450 fp 0x000000016eee8980 <redacted>+0x6dc
  pc 0x000000018a5ef55c fp 0x000000016eee89f0 <redacted>+0xec
  pc 0x000000018a5ef368 fp 0x000000016eee8a20 <redacted>+0x50
  pc 0x000000018a5eee68 fp 0x000000016eee8a80 <redacted>+0x8c
  pc 0x000000018a48d180 fp 0x000000016eee8ac0 <redacted>+0xa8
  pc 0x000000018a48d980 fp 0x000000016eee8cd0 <redacted>+0x338
  pc 0x000000018a4cebd8 fp 0x000000016eee8d10 <redacted>+0x84
  pc 0x000000018a3e11e4 fp 0x000000016eee8d60 _UIScenePerformActionsWithLifecycleActionMask+0x70
  pc 0x000000018a3e32c0 fp 0x000000016eee8e20 <redacted>+0xfc
  pc 0x000000018a3e2fb4 fp 0x000000016eee8e90 <redacted>+0xd4
  pc 0x000000018a3e1cc8 fp 0x000000016eee8fa0 <redacted>+0x260
  pc 0x000000018a3e19e8 fp 0x000000016eee9010 <redacted>+0xf4
  pc 0x000000018a3e1594 fp 0x000000016eee9050 <redacted>+0x94
  pc 0x000000018a28cc38 fp 0x000000016eee9150 <redacted>+0x2e0
  pc 0x000000018a28c260 fp 0x000000016eee91c0 _UISceneSettingsDiffActionPerformChangesWithTransitionContextAndCompletion+0xe0
  pc 0x000000018a3361d8 fp 0x000000016eee92c0 <redacted>+0x13c
  pc 0x000000018a335f64 fp 0x000000016eee9410 <redacted>+0x268
  pc 0x000000018a3358b0 fp 0x000000016eee9580 <redacted>+0xd0
  pc 0x000000018a2e13ac fp 0x000000016eee9640 <redacted>+0xf4
  pc 0x000000018a2e0ed4 fp 0x000000016eee9720 <redacted>+0x2fc
  pc 0x000000018a2e0b6c fp 0x000000016eee97b0 <redacted>+0x120
  pc 0x00000001a279330c fp 0x000000016eee98f0 <redacted>+0x120
  pc 0x00000001a277f2d8 fp 0x000000016eee9920 <redacted>+0x44
  pc 0x00000001a27998b8 fp 0x000000016eee99f0 <redacted>+0x1b4
  pc 0x00000001a2798f2c fp 0x000000016eee9ab0 <redacted>+0x120
  pc 0x00000001a2798c58 fp 0x000000016eee9af0 <redacted>+0xa8
  pc 0x00000001a279913c fp 0x000000016eee9c40 <redacted>+0x1d8
  pc 0x00000001051c5f80 fp 0x000000016eee9c50 _dispatch_client_callout+0x10
  pc 0x00000001051b07fc fp 0x000000016eee9ca0 _dispatch_block_invoke_direct+0x128
  pc 0x00000001a2795658 fp 0x000000016eee9cd0 <redacted>+0x34
  pc 0x00000001a27955d8 fp 0x000000016eee9d60 <redacted>+0xf0
  pc 0x00000001a27954b0 fp 0x000000016eee9d80 <redacted>+0x1c
  pc 0x0000000187884dc8 fp 0x000000016eee9d90 <redacted>+0x1c
  pc 0x0000000187884d5c fp 0x000000016eee9dc0 <redacted>+0xac
  pc 0x0000000187883ae0 fp 0x000000016eee9e20 <redacted>+0xe8
  pc 0x0000000187882d20 fp 0x000000016eeeab90 <redacted>+0x348
  pc 0x00000001878a77f0 fp 0x000000016eeeac10 CFRunLoopRunSpecific+0x23c
  pc 0x00000001d4afa190 fp 0x000000016eeeac70 GSEventRunModal+0xa8
  pc 0x000000018a4ce158 fp 0x000000016eeeacf0 <redacted>+0x330
  pc 0x000000018a4cc388 fp 0x000000016eeead80 UIApplicationMain+0x150
  pc 0x000000018a927eb4 fp 0x000000016eeeadc0 <redacted>+0x265c
  pc 0x0000000102b0d26c fp 0x000000016eeeae10 $sSo21UIApplicationDelegateP5UIKitE4mainyyFZ+0x78
  pc 0x0000000102b0d1e4 fp 0x000000016eeeae40 $s6Runner11AppDelegateC5$mainyyFZ+0x2c
  pc 0x0000000102b0d2e8 fp 0x000000016eeeae60 __debug_main_executable_dylib_entry_point+0x1c
  pc 0x00000001aee53a58 fp 0x000000016eeeb4c0 <redacted>+0x174c
-- End of DumpStackTrace
=== Crash occurred when compiling unknown function in unoptimized JIT mode in unknown pass
=== Flow Graph not available```

</details>


### Flutter Doctor output

<details open><summary>Doctor output</summary>

```console
[✓] Flutter (Channel stable, 3.29.0, on macOS 15.3.1 24D70 darwin-arm64, locale en-US)
[!] Android toolchain - develop for Android devices (Android SDK version 35.0.0)
    ! Some Android licenses not accepted. To resolve this, run: flutter doctor
      --android-licenses
[✓] Xcode - develop for iOS and macOS (Xcode 16.2)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2024.2)
[✓] IntelliJ IDEA Ultimate Edition (version 2024.1.1)
[✓] VS Code (version 1.97.2)
[✓] Connected device (5 available)
    ! Error: Browsing on the local area network for Nick’s iPhone. Ensure the device is
      unlocked and attached with a cable or associated with the same local area network as
      this Mac.
      The device must be opted into Developer Mode to connect wirelessly. (code -27)
[✓] Network resources

! Doctor found issues in 1 category.

[seokyongKim]

Likewise, I'm not doing a debug build on my actual iOS 18.4 beta because of that issue.
When you build relase, it works fine.
I think it's a JIT problem.

[seokyongKim]

../../../flutter/third_party/dart/runtime/vm/virtual_memory_posix.cc: 428: error: mprotect failed: 13 (Permission denied)
version=3.6.0 (stable) (Thu Dec 5 07:46:24 2024 -0800) on "ios_arm64"
pid=3252, thread=259, isolate_group=vm-isolate(0x107205400), isolate=vm-isolate(0x107369000)
os=ios, arch=arm64, comp=no, sim=no
isolate_instructions=108e375a0, vm_instructions=108e375a0
fp=16bb19560, sp=16bb19540, pc=109889864
  pc 0x0000000109889864 fp 0x000000016bb19560 Dart_DumpNativeStackTrace+0x18
  pc 0x000000010943aeb8 fp 0x000000016bb19580 dart::Assert::Fail(char const*, ...) const+0x30
  pc 0x0000000109536100 fp 0x000000016bb19a30 dart::Code::FinalizeCode(dart::FlowGraphCompiler*, dart::compiler::Assembler*, dart::Code::PoolAttachment, bool, dart::CodeStatistics*)+0x82c
  pc 0x00000001095f51c8 fp 0x000000016bb1a040 dart::StubCode::Init()+0x31c
  pc 0x0000000109485c30 fp 0x000000016bb1ab00 dart::Dart::DartInit(Dart_InitializeParams const*)+0x2a9c
  pc 0x0000000109870310 fp 0x000000016bb1ab20 Dart_Initialize+0x3c
  pc 0x0000000108f1aaf4 fp 0x000000016bb1b0f0 flutter::DartVM::Create(flutter::Settings const&, fml::RefPtr<flutter::DartSnapshot const>, fml::RefPtr<flutter::DartSnapshot const>, std::_fl::shared_ptr<flutter::IsolateNameServer>)+0x1d60
  pc 0x00000001093f17dc fp 0x000000016bb1b850 flutter::Shell::Create(flutter::PlatformData const&, flutter::TaskRunners const&, flutter::Settings, std::_fl::function<std::_fl::unique_ptr<flutter::PlatformView, std::_fl::default_delete<flutter::PlatformView>> (flutter::Shell&)> const&, std::_fl::function<std::_fl::unique_ptr<flutter::Rasterizer, std::_fl::default_delete<flutter::Rasterizer>> (flutter::Shell&)> const&, bool)+0x310
  pc 0x0000000108e3b060 fp 0x000000016bb1c5c0 -[FlutterEngine createShell:libraryURI:initialRoute:]+0x934
  pc 0x0000000108e42c4c fp 0x000000016bb1c630 -[FlutterViewController sharedSetupWithProject:initialRoute:]+0x1cc
  pc 0x0000000108e42a58 fp 0x000000016bb1c660 -[FlutterViewController awakeFromNib]+0x58
  pc 0x00000001876c0450 fp 0x000000016bb1cb30 <redacted>+0x6dc
  pc 0x000000018772f55c fp 0x000000016bb1cba0 <redacted>+0xec
  pc 0x000000018772f368 fp 0x000000016bb1cbd0 <redacted>+0x50
  pc 0x000000018772ee68 fp 0x000000016bb1cc30 <redacted>+0x8c
  pc 0x00000001875cd180 fp 0x000000016bb1cc70 <redacted>+0xa8
  pc 0x00000001875cd980 fp 0x000000016bb1ce80 <redacted>+0x338
  pc 0x000000018760ebd8 fp 0x000000016bb1cec0 <redacted>+0x84
  pc 0x00000001875211e4 fp 0x000000016bb1cf10 _UIScenePerformActionsWithLifecycleActionMask+0x70
  pc 0x00000001875232c0 fp 0x000000016bb1cfd0 <redacted>+0xfc
  pc 0x0000000187522fb4 fp 0x000000016bb1d040 <redacted>+0xd4
  pc 0x0000000187521cc8 fp 0x000000016bb1d150 <redacted>+0x260
  pc 0x00000001875219e8 fp 0x000000016bb1d1c0 <redacted>+0xf4
  pc 0x0000000187521594 fp 0x000000016bb1d200 <redacted>+0x94
  pc 0x00000001873ccc38 fp 0x000000016bb1d300 <redacted>+0x2e0
  pc 0x00000001873cc260 fp 0x000000016bb1d370 _UISceneSettingsDiffActionPerformChangesWithTransitionContextAndCompletion+0xe0
  pc 0x00000001874761d8 fp 0x000000016bb1d470 <redacted>+0x13c
  pc 0x0000000187475f64 fp 0x000000016bb1d5c0 <redacted>+0x268
  pc 0x00000001874758b0 fp 0x000000016bb1d730 <redacted>+0xd0
  pc 0x00000001874213ac fp 0x000000016bb1d7f0 <redacted>+0xf4
  pc 0x0000000187420ed4 fp 0x000000016bb1d8d0 <redacted>+0x2fc
  pc 0x0000000187420b6c fp 0x000000016bb1d960 <redacted>+0x120
  pc 0x000000019f8d330c fp 0x000000016bb1daa0 <redacted>+0x120
  pc 0x000000019f8bf2d8 fp 0x000000016bb1dad0 <redacted>+0x44
  pc 0x000000019f8d98b8 fp 0x000000016bb1dba0 <redacted>+0x1b4
  pc 0x000000019f8d8f2c fp 0x000000016bb1dc60 <redacted>+0x120
  pc 0x000000019f8d8c58 fp 0x000000016bb1dca0 <redacted>+0xa8
  pc 0x000000019f8d913c fp 0x000000016bb1ddf0 <redacted>+0x1d8
  pc 0x0000000105e25f80 fp 0x000000016bb1de00 _dispatch_client_callout+0x10
  pc 0x0000000105e107fc fp 0x000000016bb1de50 _dispatch_block_invoke_direct+0x128
  pc 0x000000019f8d5658 fp 0x000000016bb1de80 <redacted>+0x34
  pc 0x000000019f8d55d8 fp 0x000000016bb1df10 <redacted>+0xf0
  pc 0x000000019f8d54b0 fp 0x000000016bb1df30 <redacted>+0x1c
  pc 0x00000001849c4dc8 fp 0x000000016bb1df40 <redacted>+0x1c
  pc 0x00000001849c4d5c fp 0x000000016bb1df70 <redacted>+0xac
  pc 0x00000001849c3b44 fp 0x000000016bb1dfd0 <redacted>+0x14c
  pc 0x00000001849c2d20 fp 0x000000016bb1ed40 <redacted>+0x348
  pc 0x00000001849e77f0 fp 0x000000016bb1edc0 CFRunLoopRunSpecific+0x23c
  pc 0x00000001d1c3a190 fp 0x000000016bb1ee20 GSEventRunModal+0xa8
  pc 0x000000018760e158 fp 0x000000016bb1eea0 <redacted>+0x330
  pc 0x000000018760c388 fp 0x000000016bb1ef30 UIApplicationMain+0x150
  pc 0x0000000187a67eb4 fp 0x000000016bb1ef70 <redacted>+0x265c
  pc 0x00000001051341a4 fp 0x000000016bb1efc0 $sSo21UIApplicationDelegateP5UIKitE4mainyyFZ+0x78
  pc 0x000000010513411c fp 0x000000016bb1eff0 $s6Runner11AppDelegateC5$mainyyFZ+0x2c
  pc 0x0000000105134268 fp 0x000000016bb1f010 __debug_main_executable_dylib_entry_point+0x1c
  pc 0x00000001abf93a58 fp 0x000000016bb1f670 <redacted>+0x174c
-- End of DumpStackTrace
=== Crash occurred when compiling unknown function in unoptimized JIT mode in unknown pass
=== Flow Graph not available

[emreerkaslan]

I am having the same trouble after updating to ios 18.4.

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 3.29.0, on macOS 15.3.1 24D70 darwin-arm64, locale en-TR)
[✓] Android toolchain - develop for Android devices (Android SDK version 35.0.0)
[✓] Xcode - develop for iOS and macOS (Xcode 16.2)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2024.2)
[✓] VS Code (version 1.97.2)
[✓] Connected device (4 available)
[✓] Network resources

• No issues found!

version=3.5.4 (stable) (Wed Oct 16 16:18:51 2024 +0000) on "ios_arm64"
pid=1200, thread=259, isolate_group=vm-isolate(0x144b48a00), isolate=vm-isolate(0x144c8e800)
os=ios, arch=arm64, comp=no, sim=no
isolate_instructions=1173575e0, vm_instructions=1173575e0
fp=16cec96d0, sp=16cec96b0, pc=117d781a0
  pc 0x0000000117d781a0 fp 0x000000016cec96d0 Dart_DumpNativeStackTrace+0x18
  pc 0x000000011794a0e8 fp 0x000000016cec96f0 dart::Assert::Fail(char const*, ...) const+0x30
  pc 0x0000000117a4560c fp 0x000000016cec9ba0 dart::Code::FinalizeCode(dart::FlowGraphCompiler*, dart::compiler::Assembler*, dart::Code::PoolAttachment, bool, dart::CodeStatistics*)+0x874
  pc 0x0000000117b02268 fp 0x000000016cec9ed0 dart::StubCode::Init()+0x310
  pc 0x0000000117992a78 fp 0x000000016ceca990 dart::Dart::DartInit(Dart_InitializeParams const*)+0x2b6c
  pc 0x0000000117d61900 fp 0x000000016ceca9b0 Dart_Initialize+0x3c
  pc 0x0000000117433160 fp 0x000000016cecaf80 flutter::DartVM::Create(flutter::Settings const&, fml::RefPtr<flutter::DartSnapshot const>, fml::RefPtr<flutter::DartSnapshot const>, std::_fl::shared_ptr<flutter::IsolateNameServer>)+0x1d60
  pc 0x0000000117900a54 fp 0x000000016cecb6e0 flutter::Shell::Create(flutter::PlatformData const&, flutter::TaskRunners const&, flutter::Settings, std::_fl::function<std::_fl::unique_ptr<flutter::PlatformView, std::_fl::default_delete<flutter::PlatformView>> (flutter::Shell&)> const&, std::_fl::function<std::_fl::unique_ptr<flutter::Rasterizer, std::_fl::default_delete<flutter::Rasterizer>> (flutter::Shell&)> const&, bool)+0x310
  pc 0x000000011735bad0 fp 0x000000016cecc420 -[FlutterEngine createShell:libraryURI:initialRoute:]+0x538
  pc 0x0000000117364a18 fp 0x000000016cecc490 -[FlutterViewController sharedSetupWithProject:initialRoute:]+0x1cc
  pc 0x0000000117364824 fp 0x000000016cecc4c0 -[FlutterViewController awakeFromNib]+0x58
  pc 0x000000019644c450 fp 0x000000016cecc990 <redacted>+0x6dc
  pc 0x00000001964bb55c fp 0x000000016cecca00 <redacted>+0xec
  pc 0x00000001964bb368 fp 0x000000016cecca30 <redacted>+0x50
  pc 0x00000001964bae68 fp 0x000000016cecca90 <redacted>+0x8c
  pc 0x0000000196359180 fp 0x000000016ceccad0 <redacted>+0xa8
  pc 0x0000000196359980 fp 0x000000016ceccce0 <redacted>+0x338
  pc 0x000000019639abd8 fp 0x000000016ceccd20 <redacted>+0x84
  pc 0x00000001962ad1e4 fp 0x000000016ceccd70 _UIScenePerformActionsWithLifecycleActionMask+0x70
  pc 0x00000001962af2c0 fp 0x000000016cecce30 <redacted>+0xfc
  pc 0x00000001962aefb4 fp 0x000000016ceccea0 <redacted>+0xd4
  pc 0x00000001962adcc8 fp 0x000000016ceccfb0 <redacted>+0x260
  pc 0x00000001962ad9e8 fp 0x000000016cecd020 <redacted>+0xf4
  pc 0x00000001962ad594 fp 0x000000016cecd060 <redacted>+0x94
  pc 0x0000000196158c38 fp 0x000000016cecd160 <redacted>+0x2e0
  pc 0x0000000196158260 fp 0x000000016cecd1d0 _UISceneSettingsDiffActionPerformChangesWithTransitionContextAndCompletion+0xe0
  pc 0x00000001962021d8 fp 0x000000016cecd2d0 <redacted>+0x13c
  pc 0x0000000196201f64 fp 0x000000016cecd420 <redacted>+0x268
  pc 0x00000001962018b0 fp 0x000000016cecd590 <redacted>+0xd0
  pc 0x00000001961ad3ac fp 0x000000016cecd650 <redacted>+0xf4
  pc 0x00000001961aced4 fp 0x000000016cecd730 <redacted>+0x2fc
  pc 0x00000001961acb6c fp 0x000000016cecd7c0 <redacted>+0x120
  pc 0x00000001ae65f30c fp 0x000000016cecd900 <redacted>+0x120
  pc 0x00000001ae64b2d8 fp 0x000000016cecd930 <redacted>+0x44
  pc 0x00000001ae6658b8 fp 0x000000016cecda00 <redacted>+0x1b4
  pc 0x00000001ae664f2c fp 0x000000016cecdac0 <redacted>+0x120
  pc 0x00000001ae664c58 fp 0x000000016cecdb00 <redacted>+0xa8
  pc 0x00000001ae66513c fp 0x000000016cecdc50 <redacted>+0x1d8
  pc 0x0000000106039f80 fp 0x000000016cecdc60 _dispatch_client_callout+0x10
  pc 0x00000001060247fc fp 0x000000016cecdcb0 _dispatch_block_invoke_direct+0x128
  pc 0x00000001ae661658 fp 0x000000016cecdce0 <redacted>+0x34
  pc 0x00000001ae6615d8 fp 0x000000016cecdd70 <redacted>+0xf0
  pc 0x00000001ae6614b0 fp 0x000000016cecdd90 <redacted>+0x1c
  pc 0x0000000193750dc8 fp 0x000000016cecdda0 <redacted>+0x1c
  pc 0x0000000193750d5c fp 0x000000016cecddd0 <redacted>+0xac
  pc 0x000000019374fb44 fp 0x000000016cecde30 <redacted>+0x14c
  pc 0x000000019374ed20 fp 0x000000016ceceba0 <redacted>+0x348
  pc 0x00000001937737f0 fp 0x000000016cecec20 CFRunLoopRunSpecific+0x23c
  pc 0x00000001e09c6190 fp 0x000000016cecec80 GSEventRunModal+0xa8
  pc 0x000000019639a158 fp 0x000000016ceced00 <redacted>+0x330
  pc 0x0000000196398388 fp 0x000000016ceced90 UIApplicationMain+0x150
  pc 0x00000001967f3eb4 fp 0x000000016cecedd0 <redacted>+0x265c
  pc 0x000000010ac30168 fp 0x000000016cecee20 $sSo21UIApplicationDelegateP5UIKitE4mainyyFZ+0x78
  pc 0x000000010ac300e0 fp 0x000000016cecee50 $s6Runner11AppDelegateC5$mainyyFZ+0x2c
  pc 0x000000010ac301e4 fp 0x000000016cecee70 __debug_main_executable_dylib_entry_point+0x1c
  pc 0x00000001bad1fa58 fp 0x000000016cecf4d0 <redacted>+0x174c
-- End of DumpStackTrace
=== Crash occurred when compiling unknown function in unoptimized JIT mode in unknown pass
=== Flow Graph not available

[mraleph]

It seems that iOS 18.4 Beta has finally closed a long existing loophole with get-task-allow allowing to bypass code signing restrictions. The app itself can no longer write into its own executable memory and flip permission RX->RW and back. The is a special path built into kernel to allow debugserver do these things (based on private entitlement). Some preliminary analysis of kernel changes available here.

What this means for us:

• we need to go back and fallback to interpretation for development builds like we did in the early days of Flutter. That's fairly straightforward - but we would need to tackle performance implications to the extent we can. (Another thing is dart:ffi - we would need to write generic stubs for ABI marshalling which do not rely on JIT code generation.) cc @a-siva @alexmarkov @mkustermann @dcharkes
• In the interim we need to warn people that they would not be able to develop on iOS 18.4 (release and profile builds are fine though) - so they should not update their phones if they want to use hot reload and stuff. cc @jmagman @zanderso @jtmcdole @johnmccutchan for visibility.

[a-siva]

I have created dart-lang/sdk#60202 on the Dart side for this issue, please discuss all issues related to interpreting over there.