Crash with [MXCrossSigning refreshStateWithSuccess]

[manuroe]

It happened more since 1.5.4 and it is happening much much more in 1.6.0:

0   libsystem_kernel.dylib        	0x00000001b8fb4df0 __open + 8
1   libsystem_kernel.dylib        	0x00000001b8fb51d4 open + 40 (open-base.c:101)
2   Realm                         	0x00000001042244c4 realm::util::File::lock+ 2622660 (bool, bool) + 556
3   Realm                         	0x00000001040cf7a8 realm::DB::close_internal+ 1226664 (std::__1::unique_lock<realm::util::InterprocessMutex>, bool) + 424
4   Realm                         	0x00000001040cdb90 realm::DB::close+ 1219472 (bool) + 164
5   Realm                         	0x00000001040cf0d8 realm::DB::~DB+ 1224920 () + 28
6   Realm                         	0x0000000104305bec realm::_impl::RealmCoordinator::~RealmCoordinator+ 3546092 () + 1188
7   Realm                         	0x000000010437da28 realm::Realm::~Realm+ 4037160 () + 256
8   Realm                         	0x0000000103fb9548 std::__1::__shared_count::__release_shared() + 40 (memory:3169)
9   Realm                         	0x0000000103fb9548 std::__1::__shared_weak_count::__release_shared() + 40 (memory:3211)
10  Realm                         	0x0000000103fb9548 std::__1::shared_ptr<realm::Realm>::~shared_ptr() + 64 (memory:3884)
11  libobjc.A.dylib               	0x000000019abd7f18 object_cxxDestructFromClass(objc_object*, objc_class*) + 116 (objc-class.mm:455)
12  libobjc.A.dylib               	0x000000019abd4c14 objc_destructInstance + 80 (objc-class.mm:469)
13  libobjc.A.dylib               	0x000000019abde338 _objc_rootDealloc + 80 (objc-runtime-new.mm:8189)
14  Realm                         	0x000000010407305c -[RLMRealm dealloc] + 92 (RLMRealm.mm:751)
15  libobjc.A.dylib               	0x000000019abd7f18 object_cxxDestructFromClass(objc_object*, objc_class*) + 116 (objc-class.mm:455)
16  libobjc.A.dylib               	0x000000019abd4c14 objc_destructInstance + 80 (objc-class.mm:469)
17  libobjc.A.dylib               	0x000000019abde338 _objc_rootDealloc + 80 (objc-runtime-new.mm:8189)
18  Realm                         	0x0000000103fe3670 -[RLMObjectBase dealloc] + 68 (RLMObjectBase.mm:93)
19  MatrixSDK                     	0x000000010396f894 -[MXRealmCryptoStore crossSigningKeysForUser:] + 300 (MXRealmCryptoStore.m:740)
20  MatrixSDK                     	0x0000000103878930 -[MXCrossSigning isSelfTrusted] + 280880 (MXCrossSigning.m:0)
21  MatrixSDK                     	0x0000000103877e04 -[MXCrossSigning computeState] + 278020 (MXCrossSigning.m:640)
22  MatrixSDK                     	0x00000001038770a0 __50-[MXCrossSigning refreshStateWithSuccess:failure:]_block_invoke + 274592 (MXCrossSigning.m:506)
23  libdispatch.dylib             	0x000000018233bc04 _dispatch_call_block_and_release + 32 (init.c:1516)
24  libdispatch.dylib             	0x000000018233d950 _dispatch_client_callout + 20 (object.m:560)
25  libdispatch.dylib             	0x000000018234bd30 _dispatch_main_queue_callback_4CF + 940 (inline_internal.h:2597)
26  CoreFoundation                	0x0000000182683ce4 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 16 (CFRunLoop.c:1795)
27  CoreFoundation                	0x000000018263debc __CFRunLoopRun + 2540 (CFRunLoop.c:3144)
28  CoreFoundation                	0x00000001826513c8 CFRunLoopRunSpecific + 600 (CFRunLoop.c:3268)
29  GraphicsServices              	0x000000019de6238c GSEventRunModal + 164 (GSEvent.c:2200)
30  UIKitCore                     	0x0000000184ff70bc -[UIApplication _run] + 1100 (UIApplication.m:3457)
31  UIKitCore                     	0x0000000184d74be8 UIApplicationMain + 2124 (UIApplication.m:5013)
32  Riot                          	0x00000001002c2c38 main + 68 (AppDelegate.swift:21)
33  dyld                          	0x0000000101f69a24 start + 520 (dyldMain.cpp:876)

[manuroe]

The app does not offer to send a crash report.
When debugging, the session just stops with Message from debugger: Terminated due to signal 9.

The device console provides a bit more information:

error	18:28:16.304610+0300	runningboardd	[application<im.vector.app>:16602] suspended with locked system files:
/var/mobile/Containers/Shared/AppGroup/437E30B0-F762-4115-93A3-63C5DA2742A4/MXRealmCryptoStore/@xxxxxx:matrix.org.realm.management/access_control.control.mx
/var/mobile/Containers/Shared/AppGroup/437E30B0-F762-4115-93A3-63C5DA2742A4/MXRealmCryptoStore/@xxxxxx:matrix.org.realm.management/access_control.write.mx
error	18:28:16.304738+0300	runningboardd	[application<im.vector.app>:16602] locked files not in allowed directories: /var/mobile/Containers/Data/Application/9174ECDE-D4CE-45E1-8155-513CE7AEB32D
/var/mobile/Containers/Data/Application/9174ECDE-D4CE-45E1-8155-513CE7AEB32D/tmp
default	18:28:16.305041+0300	runningboardd	[application<im.vector.app>:16602] Terminating with context: <RBSTerminateContext| domain:15 code:0xDEAD10CC explanation:[application<im.vector.app>:16602] was suspended with locked system files:
/var/mobile/Containers/Shared/AppGroup/437E30B0-F762-4115-93A3-63C5DA2742A4/MXRealmCryptoStore/@xxxxxx:matrix.org.realm.management/access_control.control.mx
/var/mobile/Containers/Shared/AppGroup/437E30B0-F762-4115-93A3-63C5DA2742A4/MXRealmCryptoStore/@xxxxxx:matrix.org.realm.management/access_control.write.mx
not in allowed directories:
/var/mobile/Containers/Data/Application/9174ECDE-D4CE-45E1-8155-513CE7AEB32D
/var/mobile/Containers/Data/Application/9174ECDE-D4CE-45E1-8155-513CE7AEB32D/tmp reportType:CrashLog maxTerminationResistance:Absolute>
default	18:28:16.305186+0300	runningboardd	[application<im.vector.app>:16602] terminate_with_reason() success

[manuroe]

It seems to be related to a Realm https:/realm/realm-cocoa/issues/6671 where you cannot access the db while the app is in background.