Regression: iOS upgrading 57 -> 59 lots of crashes "Exception in HostObject::get: <unknown>"

[DimitryDushkin]

💥 Regression Report

We've released iOS app with upgrade RN from 0.57 to 0.59.4 and receiving a lot of crash reports (like 5% of users so far)

Crash:
Crash file

Application Specific Information:
*** Terminating app due to uncaught exception 'RCTFatalException: Unhandled JS Exception: Exception in HostObject::get: <unknown>', reason: 'Unhandled JS Exception: Exception in HostObject::get: <unknown>, stack:
h@2:1670
h@2:1670
h@2:1670
h@2:1670
h@2:1670
h@2:1670
h@2:1670
d@2:868
global code@12:4
'

Thread 7 crashed with ARM-64 Thread State:

Extra Information:

Application Stats:
{
    "active_time_since_last_crash": 7.45225e+10,
    "active_time_since_launch": 0,
    "application_active": false,
    "application_in_foreground": true,
    "background_time_since_last_crash": 4.64477e+10,
    "background_time_since_launch": 0,
    "launches_since_last_crash": 419,
    "sessions_since_last_crash": 727,
    "sessions_since_launch": 1
}

CrashDoctor Diagnosis: Application threw exception RCTFatalException: Unhandled JS Exception: Exception in HostObject::get: <unknown>: Unhandled JS Exception: Exception in HostObject::get: <unknown>, stack:
h@2:1670
h@2:1670
h@2:1670
h@2:1670
h@2:1670
h@2:1670
h@2:1670
d@2:868
global code@12:4

Originated at or in a subcall of facebook::react::JSIExecutor::defaultTimeoutInvoker(std::__1::function<void ()> const&, std::__1::function<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > ()>)

Last working version

0.57

Worked up to version:

Stopped working in version:
0.59.4

To Reproduce

Random and rare crash on app startup.

Expected Behavior

Code Example

Environment

  React Native Environment Info:
    System:
      OS: macOS 10.14.3
      CPU: (8) x64 Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz
      Memory: 50.57 MB / 16.00 GB
      Shell: 3.0.2 - /usr/local/bin/fish
    Binaries:
      Node: 11.5.0 - ~/.nvm/versions/node/v11.5.0/bin/node
      Yarn: 1.15.2 - /usr/local/bin/yarn
      npm: 6.9.0 - ~/.nvm/versions/node/v11.5.0/bin/npm
      Watchman: 4.9.0 - /usr/local/bin/watchman
    SDKs:
      iOS SDK:
        Platforms: iOS 12.2, macOS 10.14, tvOS 12.2, watchOS 5.2
    IDEs:
      Android Studio: 3.3 AI-182.5107.16.33.5264788
      Xcode: 10.2.1/10E1001 - /usr/bin/xcodebuild
    npmPackages:
      react: 16.8.6 => 16.8.6
      react-native: 0.59.4 => 0.59.4

[DimitryDushkin]

I've tried to put breakpoints near

react-native/ReactCommon/jsi/JSCRuntime.cpp

Line 669 in dcc40a6

auto proxy = static_cast<HostObjectProxy*>(JSObjectGetPrivate(object));

, but it is not executed in runtime.

[thymikee]

@mhorowitz the error points to the code you wrote in a23fb1a, could you advise?

[DimitryDushkin]

We've added this patch, hope it will help us to find crash source

--- node_modules/react-native/ReactCommon/jsi/JSCRuntime.cpp	2019-04-26 17:08:37.000000000 +0300
+++ node_modules/react-native/ReactCommon/jsi/JSCRuntime.cpp	2019-04-26 17:08:42.000000000 +0300
@@ -565,7 +565,7 @@
         auto excValue =
             rt.global()
                 .getPropertyAsFunction(rt, "Error")
-                .call(rt, "Exception in HostObject::get: <unknown>");
+                .call(rt, std::string("Exception in HostObject::get:") + JSStringToSTLString(propertyName));
         *exception = rt.valueRef(excValue);
         return JSValueMakeUndefined(ctx);
       }

[DimitryDushkin]

We've found the problem — getting native module with buggy constantsToExport caused the error. So it is not RN 59 problem. Still native module name in crash will be very helpful, so I proposed some small change in #24633