React Native app fails on launch on one iPhone only, bootstrapping failed - ios

Question

We've run into an unusual situation in which an ad-hoc build of our app crashes on one specific user's iPhone (iPhone 12 Pro Max). Other users with the same device have no issue. This device is running the iOS 15 Beta (8, I believe), but so are other devices that work.
The behavior is that the app launches, the splash screen is briefly shown, and then the app disappears. There are no crash logs for the event, but I do see entries in the log that indicate bootstrapping has failed. The error message is a bit inscrutable, so I'm not sure what to look at.
This is all complicated by it not being an actual native app, as it is written using React Native. So debugging is problematic.
Looking at the log below (see the 11:33:43.698190-0400 line), does anyone have a suggestion on what I should look for? Out of 60 testers, this is the only phone with the issue.
default 11:33:43.608231-0400 Spotlight [FBSSystemService][0xe7c9] Sending request to open "com.foo.mobile.thisapp"
default 11:33:43.608625-0400 SpringBoard [FBSystemService][0xe7c9] Received request to open "com.foo.mobile.thisapp" from Spotlight:406.
default 11:33:43.608738-0400 SpringBoard Received trusted open application request for "com.foo.mobile.thisapp" from <FBApplicationProcess: 0x1084c37e0; application<com.apple.Spotlight>:406(v468)>.
default 11:33:43.635600-0400 SpringBoard Executing request: <SBMainWorkspaceTransitionRequest: 0x28344de60; eventLabel: OpenApplication(sceneID:com.foo.mobile.thisapp-default)ForRequester(Spotlight.406); display: Main; source: Spotlight>
default 11:33:43.647737-0400 SpringBoard [FBWorkspaceEvent] Executing: <FBWorkspaceEvent: 0x284665a00; OpenApplication(sceneID:com.foo.mobile.thisapp-default)ForRequester(Spotlight.406)>
default 11:33:43.649306-0400 SpringBoard Asked to bootstrap a new process with identity: application<com.foo.mobile.thisapp>
default 11:33:43.649338-0400 SpringBoard Creating process (sync=true) with identity: application<com.foo.mobile.thisapp>
default 11:33:43.649426-0400 SpringBoard Created <FBWorkspace: 0x283194210; application<com.foo.mobile.thisapp>>
default 11:33:43.649518-0400 SpringBoard Bootstrapping application<com.foo.mobile.thisapp> with intent foreground-interactive
default 11:33:43.650264-0400 SpringBoard [Main] dispatch event:
<SBSceneReadySwitcherModifierEvent: 0x284698320; type: SceneReady; appLayout: <SBAppLayout: 0x281e6c080; primary: com.foo.mobile.thisapp:default; environment: main> {
configuration = full;
environment = main;
layoutItems = {
primary = <SBDisplayItem: 0x2849d13b0> {
type = App;
bundleIdentifier = com.foo.mobile.thisapp;
uniqueIdentifier = sceneID:com.foo.mobile.thisapp-default;
};
}
}>
default 11:33:43.654268-0400 runningboardd Acquiring assertion targeting application<com.foo.mobile.thisapp> from originator [daemon<com.apple.SpringBoard>:67] with description <RBSAssertionDescriptor| "FBApplicationProcess" ID:34-67-63886 target:application<com.foo.mobile.thisapp> attributes:[
<RBSDomainAttribute| domain:"com.apple.frontboard" name:"Bootstrap-Foreground" sourceEnvironment:"(null)">,
<RBSDomainAttribute| domain:"com.apple.frontboard" name:"Visibility" sourceEnvironment:"(null)">
]>
default 11:33:43.654411-0400 runningboardd Assertion 34-67-63886 (target:application<com.foo.mobile.thisapp>) will be created as active
default 11:33:43.654645-0400 runningboardd Executing launch request for application<com.foo.mobile.thisapp> (FBApplicationProcess)
default 11:33:43.654810-0400 runningboardd Creating and launching job for: application<com.foo.mobile.thisapp>
default 11:33:43.654988-0400 runningboardd _mutateContextIfNeeded called for com.foo.mobile.thisapp
default 11:33:43.671674-0400 mediaserverd <<<< FigCaptureDisplayLayoutMonitor >>>> -[FigCaptureDisplayLayoutMonitor _updateCurrentLayout:]: <FBSDisplayLayout: 0x1392c2630; displayIdentity: Main> { bounds = {{0, 0}, {428, 926}}; interfaceOrientation = "portrait (1)"; backlightLevel = 100; elements = { <SBSDisplayLayoutElement: 0x13922f140; com.apple.springboard.spotlight; frame: {{0, 0}, {428, 926}}; level: 0; role: embedded>; <SBSDisplayLayoutElement: 0x139270130; sceneID:com.foo.mobile.thisapp-default; bundleID: com.foo.mobile.thisapp; frame: {{0, 0}, {428, 926}}; level: 1; role: primary>; } timestamp = September 2, 2021 at 11:33:43 AM EDT;}
default 11:33:43.673667-0400 SpringBoard [Main] dispatch event:
<SBTransitionSwitcherModifierEvent: 0x283a3df00; type: MainTransition; transitionID: B611A8E7-B802-4298-8FB7-A9E960141B96; phase: Prepare; animated: YES; fromAppLayout: 0x0; toAppLayout: <SBAppLayout: 0x281e6c080; primary: com.foo.mobile.thisapp:default; environment: main>; fromEnvironmentMode: home-screen; toEnvironmentMode: application; pendingTermination: {(
)}; isSpotlightTransition: YES; dosidoTransitionDirection: 0>
default 11:33:43.697614-0400 runningboardd Invalidating assertion 34-67-63886 (target:application<com.foo.mobile.thisapp>) from originator [daemon<com.apple.SpringBoard>:67]
error 11:33:43.698190-0400 SpringBoard Bootstrapping failed for <FBApplicationProcess: 0x1084e9b50; application<com.foo.mobile.thisapp>:<invalid>> with error: <NSError: 0x28498d350; domain: RBSRequestErrorDomain; code: 5; reason: "Launch failed."> {
NSUnderlyingError = <NSError: 0x28498e2e0; domain: NSPOSIXErrorDomain; code: 85>;
}
default 11:33:43.698318-0400 SpringBoard [application<com.foo.mobile.thisapp>:-1] Now flagged as pending exit for reason: Bootstrap failed
default 11:33:43.698349-0400 SpringBoard [application<com.foo.mobile.thisapp>:-1] Connection to remote process was not established.

Answer 1

Interestingly enough, this appears to be some side effect of compiling with Fastlane and then using Fastlane to upload the artifact. If I archive the project manually and upload it to Firebase, the app works fine on the iPhone in question.