ICU causes crash on iOS 17.4 simulator

[rolfbjarne]

Description

App crashes when iOS starts using its own ICU code.

I'm guessing it's because of a symbol clash with Mono's ICU symbols.

Reproduction Steps

1. Install Xcode 15.3 beta 3.
2. Create a new iOS project: dotnet new ios
3. Add this to FinishedLaunching in AppDelegate.cs:

var date = NSDate.Now;
var locale = NSLocale.SystemLocale;
var str = date.DescriptionWithLocale (locale);

4. Run in an iOS 17.4 simulator

Note: an iOS 17.2 simulator works just fine.

Expected behavior

No crash.

Actual behavior

Crash:

Thread 0 Crashed:: tid_103 Dispatch queue: com.apple.main-thread
0   libsystem_kernel.dylib        	       0x1129293b0 __pthread_kill + 8
1   libsystem_pthread.dylib       	       0x112557130 pthread_kill + 256
2   libsystem_c.dylib             	       0x1801655c0 abort + 104
3   libmonosgen-2.0.dylib         	       0x113316bcc sigabrt_signal_handler.cold.1 + 48
4   libmonosgen-2.0.dylib         	       0x113043a60 sigabrt_signal_handler + 196
5   libsystem_platform.dylib      	       0x1123237e0 _sigtramp + 52
6   libsystem_pthread.dylib       	       0x112557130 pthread_kill + 256
7   libsystem_c.dylib             	       0x1801655c0 abort + 104
8   libsystem_malloc.dylib        	       0x1801e378c malloc_vreport + 900
9   libsystem_malloc.dylib        	       0x1801e3950 malloc_report + 60
10  libsystem_malloc.dylib        	       0x1801d78a0 find_zone_and_free + 456
11  libicucore.A.dylib            	       0x181dbf2a0 icu::Locale::setToBogus() + 48
12  libicucore.A.dylib            	       0x181dc0c44 icu::Locale::operator=(icu::Locale const&) + 36
13  libicucore.A.dylib            	       0x181f2e5f4 icu::number::LocalizedNumberFormatter::LocalizedNumberFormatter(icu::number::impl::MacroProps&&, icu::Locale const&) + 212
14  libicucore.A.dylib            	       0x181eda738 icu::DecimalFormat::touch(UErrorCode&) + 204
15  libicucore.A.dylib            	       0x181edade8 icu::DecimalFormat::DecimalFormat(icu::UnicodeString const&, icu::DecimalFormatSymbols*, UNumberFormatStyle, UErrorCode&) + 328
16  libicucore.A.dylib            	       0x181f491b0 icu::NumberFormat::makeInstance(icu::Locale const&, UNumberFormatStyle, signed char, UErrorCode&) + 1600
17  libicucore.A.dylib            	       0x181f489e8 icu::LocaleCacheKey<icu::SharedNumberFormat>::createObject(void const*, UErrorCode&) const + 84
18  libicucore.A.dylib            	       0x181e6dae0 icu::UnifiedCache::_get(icu::CacheKeyBase const&, icu::SharedObject const*&, void const*, UErrorCode&) const + 140
19  libicucore.A.dylib            	       0x181f495d0 0x181dbd000 + 1623504
20  libicucore.A.dylib            	       0x181f48b10 0x181dbd000 + 1620752
21  libicucore.A.dylib            	       0x181f4864c icu::NumberFormat::createInstance(icu::Locale const&, UNumberFormatStyle, UErrorCode&) + 92
22  libicucore.A.dylib            	       0x181dcacf4 icu::SimpleDateFormat::initialize(icu::Locale const&, UErrorCode&) + 544
23  libicucore.A.dylib            	       0x181dc6030 icu::SimpleDateFormat::construct(icu::DateFormat::EStyle, icu::DateFormat::EStyle, icu::Locale const&, UErrorCode&) + 1952
24  libicucore.A.dylib            	       0x181dc5838 icu::SimpleDateFormat::SimpleDateFormat(icu::DateFormat::EStyle, icu::DateFormat::EStyle, icu::Locale const&, UErrorCode&) + 160
25  libicucore.A.dylib            	       0x181dc5720 icu::DateFormat::create(icu::DateFormat::EStyle, icu::DateFormat::EStyle, icu::Locale const&) + 144
26  libicucore.A.dylib            	       0x181dc5590 udat_open + 392
27  CoreFoundation                	       0x18049f540 __cficu_udat_open + 68
28  CoreFoundation                	       0x1803c3d68 __ResetUDateFormat + 484
29  CoreFoundation                	       0x1803c367c __CreateCFDateFormatter + 320
30  CoreFoundation                	       0x18049b4c0 -[NSDate descriptionWithLocale:] + 96
31  libxamarin-dotnet-debug.dylib 	       0x1129fcb8c xamarin_dyn_objc_msgSend + 160
32  newios                        	       0x109125ab8 wrapper_managed_to_native_ObjCRuntime_Messaging_NativeHandle_objc_msgSend_NativeHandle_intptr_intptr_ObjCRuntime_NativeHandle + 168
33  newios                        	       0x10843723c Foundation_NSDate_DescriptionWithLocale_Foundation_NSLocale + 140 (NSDate.g.cs:173)
34  newios                        	       0x104f5a504 newios_AppDelegate_FinishedLaunching_UIKit_UIApplication_Foundation_NSDictionary + 500 (AppDelegate.cs:17)

Full crash report: https://gist.github.com/rolfbjarne/9fcedeb59d0521c4c9bb931056bba15c

Regression?

Yes. Fortunately it seems to only affect the simulator, and not device.

Known Workarounds

Disable globalization and make the app link mono statically works:

<PropertyGroup>
  <_LibXamarinLinkMode>static</_LibXamarinLinkMode>
  <_LibMonoLinkMode>static</_LibMonoLinkMode>
  <InvariantGlobalization>true</InvariantGlobalization>
</PropertyGroup>
<Target Name="_FixMonoLinkMode" AfterTargets="_MonoReadAvailableComponentsManifest">
  <ItemGroup>
    <_MonoRuntimeComponentLinking Remove="dynamic" />
    <_MonoRuntimeComponentLinking Include="static" RuntimeIdentifier="iossimulator-arm64" />
  </ItemGroup>
</Target>

Configuration

$ dotnet --info
.NET SDK:
 Version:           8.0.100
 Commit:            57efcf1350
 Workload version:  8.0.100-manifests.5638171e

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  14.4
 OS Platform: Darwin
 RID:         osx-arm64
 Base Path:   /usr/local/share/dotnet/sdk/8.0.100/

.NET workloads installed:
 Workload version: 8.0.100-manifests.5638171e
 [ios]
   Installation Source: SDK 8.0.100
   Manifest Version:    17.2.8022/8.0.100
   Manifest Path:       /usr/local/share/dotnet/sdk-manifests/8.0.100/microsoft.net.sdk.ios/17.2.8022/WorkloadManifest.json
   Install Type:        FileBased


Host:
  Version:      8.0.0
  Architecture: arm64
  Commit:       5535e31a71

.NET SDKs installed:
  8.0.100 [/usr/local/share/dotnet/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 8.0.0 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 8.0.0 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
  x64   [/usr/local/share/dotnet/x64]
    registered at [/etc/dotnet/install_location_x64]

Environment variables:
  Not set

global.json file:
  Not found

Other information

No response

[rolfbjarne]

CC @steveisok

This completely breaks the simulator for us, so it's rather urgent to get it fixed (and any fixes would have to be backported to .NET 8)

Tagging subscribers to this area: @dotnet/area-system-globalization
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

App crashes when iOS starts using its own ICU code.

I'm guessing it's because of a symbol clash with Mono's ICU symbols.

Reproduction Steps

1. Install Xcode 15.3 beta 3.
2. Create a new iOS project: dotnet new ios
3. Add this to FinishedLaunching in AppDelegate.cs:

var date = NSDate.Now;
var locale = NSLocale.SystemLocale;
var str = date.DescriptionWithLocale (locale);

4. Run in an iOS 17.4 simulator

Note: an iOS 17.2 simulator works just fine.

Expected behavior

No crash.

Actual behavior

Crash:

Thread 0 Crashed:: tid_103 Dispatch queue: com.apple.main-thread
0   libsystem_kernel.dylib        	       0x1129293b0 __pthread_kill + 8
1   libsystem_pthread.dylib       	       0x112557130 pthread_kill + 256
2   libsystem_c.dylib             	       0x1801655c0 abort + 104
3   libmonosgen-2.0.dylib         	       0x113316bcc sigabrt_signal_handler.cold.1 + 48
4   libmonosgen-2.0.dylib         	       0x113043a60 sigabrt_signal_handler + 196
5   libsystem_platform.dylib      	       0x1123237e0 _sigtramp + 52
6   libsystem_pthread.dylib       	       0x112557130 pthread_kill + 256
7   libsystem_c.dylib             	       0x1801655c0 abort + 104
8   libsystem_malloc.dylib        	       0x1801e378c malloc_vreport + 900
9   libsystem_malloc.dylib        	       0x1801e3950 malloc_report + 60
10  libsystem_malloc.dylib        	       0x1801d78a0 find_zone_and_free + 456
11  libicucore.A.dylib            	       0x181dbf2a0 icu::Locale::setToBogus() + 48
12  libicucore.A.dylib            	       0x181dc0c44 icu::Locale::operator=(icu::Locale const&) + 36
13  libicucore.A.dylib            	       0x181f2e5f4 icu::number::LocalizedNumberFormatter::LocalizedNumberFormatter(icu::number::impl::MacroProps&&, icu::Locale const&) + 212
14  libicucore.A.dylib            	       0x181eda738 icu::DecimalFormat::touch(UErrorCode&) + 204
15  libicucore.A.dylib            	       0x181edade8 icu::DecimalFormat::DecimalFormat(icu::UnicodeString const&, icu::DecimalFormatSymbols*, UNumberFormatStyle, UErrorCode&) + 328
16  libicucore.A.dylib            	       0x181f491b0 icu::NumberFormat::makeInstance(icu::Locale const&, UNumberFormatStyle, signed char, UErrorCode&) + 1600
17  libicucore.A.dylib            	       0x181f489e8 icu::LocaleCacheKey<icu::SharedNumberFormat>::createObject(void const*, UErrorCode&) const + 84
18  libicucore.A.dylib            	       0x181e6dae0 icu::UnifiedCache::_get(icu::CacheKeyBase const&, icu::SharedObject const*&, void const*, UErrorCode&) const + 140
19  libicucore.A.dylib            	       0x181f495d0 0x181dbd000 + 1623504
20  libicucore.A.dylib            	       0x181f48b10 0x181dbd000 + 1620752
21  libicucore.A.dylib            	       0x181f4864c icu::NumberFormat::createInstance(icu::Locale const&, UNumberFormatStyle, UErrorCode&) + 92
22  libicucore.A.dylib            	       0x181dcacf4 icu::SimpleDateFormat::initialize(icu::Locale const&, UErrorCode&) + 544
23  libicucore.A.dylib            	       0x181dc6030 icu::SimpleDateFormat::construct(icu::DateFormat::EStyle, icu::DateFormat::EStyle, icu::Locale const&, UErrorCode&) + 1952
24  libicucore.A.dylib            	       0x181dc5838 icu::SimpleDateFormat::SimpleDateFormat(icu::DateFormat::EStyle, icu::DateFormat::EStyle, icu::Locale const&, UErrorCode&) + 160
25  libicucore.A.dylib            	       0x181dc5720 icu::DateFormat::create(icu::DateFormat::EStyle, icu::DateFormat::EStyle, icu::Locale const&) + 144
26  libicucore.A.dylib            	       0x181dc5590 udat_open + 392
27  CoreFoundation                	       0x18049f540 __cficu_udat_open + 68
28  CoreFoundation                	       0x1803c3d68 __ResetUDateFormat + 484
29  CoreFoundation                	       0x1803c367c __CreateCFDateFormatter + 320
30  CoreFoundation                	       0x18049b4c0 -[NSDate descriptionWithLocale:] + 96
31  libxamarin-dotnet-debug.dylib 	       0x1129fcb8c xamarin_dyn_objc_msgSend + 160
32  newios                        	       0x109125ab8 wrapper_managed_to_native_ObjCRuntime_Messaging_NativeHandle_objc_msgSend_NativeHandle_intptr_intptr_ObjCRuntime_NativeHandle + 168
33  newios                        	       0x10843723c Foundation_NSDate_DescriptionWithLocale_Foundation_NSLocale + 140 (NSDate.g.cs:173)
34  newios                        	       0x104f5a504 newios_AppDelegate_FinishedLaunching_UIKit_UIApplication_Foundation_NSDictionary + 500 (AppDelegate.cs:17)

Full crash report: https://gist.github.com/rolfbjarne/9fcedeb59d0521c4c9bb931056bba15c

Regression?

Yes. Fortunately it seems to only affect the simulator, and not device.

Known Workarounds

Disable globalization and make the app link mono statically works:

<PropertyGroup>
  <_LibXamarinLinkMode>static</_LibXamarinLinkMode>
  <_LibMonoLinkMode>static</_LibMonoLinkMode>
  <InvariantGlobalization>true</InvariantGlobalization>
</PropertyGroup>
<Target Name="_FixMonoLinkMode" AfterTargets="_MonoReadAvailableComponentsManifest">
  <ItemGroup>
    <_MonoRuntimeComponentLinking Remove="dynamic" />
    <_MonoRuntimeComponentLinking Include="static" RuntimeIdentifier="iossimulator-arm64" />
  </ItemGroup>
</Target>

Configuration

$ dotnet --info
.NET SDK:
 Version:           8.0.100
 Commit:            57efcf1350
 Workload version:  8.0.100-manifests.5638171e

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  14.4
 OS Platform: Darwin
 RID:         osx-arm64
 Base Path:   /usr/local/share/dotnet/sdk/8.0.100/

.NET workloads installed:
 Workload version: 8.0.100-manifests.5638171e
 [ios]
   Installation Source: SDK 8.0.100
   Manifest Version:    17.2.8022/8.0.100
   Manifest Path:       /usr/local/share/dotnet/sdk-manifests/8.0.100/microsoft.net.sdk.ios/17.2.8022/WorkloadManifest.json
   Install Type:        FileBased


Host:
  Version:      8.0.0
  Architecture: arm64
  Commit:       5535e31a71

.NET SDKs installed:
  8.0.100 [/usr/local/share/dotnet/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 8.0.0 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 8.0.0 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
  x64   [/usr/local/share/dotnet/x64]
    registered at [/etc/dotnet/install_location_x64]

Environment variables:
  Not set

global.json file:
  Not found

Other information

No response

Author:	rolfbjarne
Assignees:	-
Labels:	area-System.Globalization, untriaged, os-ios
Milestone:	-

[tarekgh]

CC @akoeplinger

[vitek-karas]

/cc @matouskozak @ivanpovazan

[lewing]

@rolfbjarne @tarekgh @vitek-karas this is net8 so it isn't using hybrid globalization

[steveisok]

CC @steveisok

This completely breaks the simulator for us, so it's rather urgent to get it fixed (and any fixes would have to be backported to .NET 8)

Weird, I'm mentioned, but got no notification of this. @rolfbjarne confirming this is off of a .net 8 runtime?