Bug 2024298 - Fix edge case when errors occur on a multi-pref experiment in Nimbus

[ohall-m]

A bad unwrap occurs when a multi-pref experiment fails.

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[ohall-m]

Some background:

Given FML like this:

  gecko-nimbus-validation-multi-pref-user:
    description: "Feature for validating Nimbus Gecko functionality with multiple preference types on user branch"
    variables:
      anchor-color-dark:
        description: "Shipped default #00CADB"
        type: String
        default: "#000000"
        gecko-pref:
          pref: "browser.anchor_color.dark"
          branch: "user"
      autofocus:
        description: "Shipped default false"
        type: Boolean
        default: false
        gecko-pref:
          pref: "browser.autofocus"
          branch: "default"

When they both fail to set, they try to unenroll. Right now, the second one hits:

03-18 11:54:36.481 17377 17377 D AndroidRuntime: Shutting down VM
03-18 11:54:36.482 17377 17377 E AndroidRuntime: FATAL EXCEPTION: main
03-18 11:54:36.482 17377 17377 E AndroidRuntime: Process: org.mozilla.fenix.debug, PID: 17377
03-18 11:54:36.482 17377 17377 E AndroidRuntime: org.mozilla.geckoview.GeckoResult$UncaughtException: org.mozilla.experiments.nimbus.internal.InternalException: called `Option::unwrap()` on a `None` value
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at org.mozilla.geckoview.GeckoResult.dispatchLocked(GeckoResult.java:782)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at org.mozilla.geckoview.GeckoResult.completeExceptionally(GeckoResult.java:925)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at org.mozilla.geckoview.GeckoResult.lambda$thenInternal$6(GeckoResult.java:606)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at org.mozilla.geckoview.GeckoResult.$r8$lambda$82f7lYxeXTzVvMgd9wZnqr4Ug34(Unknown Source:0)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at org.mozilla.geckoview.GeckoResult$$ExternalSyntheticLambda7.run(D8$$SyntheticClass:0)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at org.mozilla.geckoview.GeckoResult.lambda$dispatchLocked$7(GeckoResult.java:797)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at org.mozilla.geckoview.GeckoResult$$ExternalSyntheticLambda8.run(D8$$SyntheticClass:0)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at android.os.Handler.handleCallback(Handler.java:958)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at android.os.Handler.dispatchMessage(Handler.java:99)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at android.os.Looper.loopOnce(Looper.java:205)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at android.os.Looper.loop(Looper.java:294)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at android.app.ActivityThread.main(ActivityThread.java:8177)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at java.lang.reflect.Method.invoke(Native Method)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:552)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:971)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: Caused by: org.mozilla.experiments.nimbus.internal.InternalException: called `Option::unwrap()` on a `None` value
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at org.mozilla.experiments.nimbus.internal.NimbusKt.uniffiCheckCallStatus(nimbus.kt:384)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at org.mozilla.experiments.nimbus.internal.NimbusKt.access$uniffiCheckCallStatus(nimbus.kt:1)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at org.mozilla.experiments.nimbus.internal.NimbusClient.unenrollForGeckoPref(nimbus.kt:3101)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at org.mozilla.experiments.nimbus.Nimbus.unenrollForGeckoPref(Nimbus.kt:461)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at org.mozilla.fenix.experiments.prefhandling.NimbusGeckoPrefHandler.handleErrors(NimbusGeckoPrefHandler.kt:171)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at org.mozilla.fenix.experiments.prefhandling.NimbusGeckoPrefHandler.applyEnrollmentPrefs$lambda$0(NimbusGeckoPrefHandler.kt:323)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at org.mozilla.fenix.experiments.prefhandling.NimbusGeckoPrefHandler.$r8$lambda$xCnViHOCuX-0NDvgsfw2YU3Up-Q(Unknown Source:0)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at org.mozilla.fenix.experiments.prefhandling.NimbusGeckoPrefHandler$$ExternalSyntheticLambda3.invoke(D8$$SyntheticClass:0)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at mozilla.components.browser.engine.gecko.GeckoEngine.setBrowserPrefs$lambda$1(GeckoEngine.kt:1300)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at mozilla.components.browser.engine.gecko.GeckoEngine.$r8$lambda$STYT63XFj_Wj9bImnp6WV-iEtJY(Unknown Source:0)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at mozilla.components.browser.engine.gecko.GeckoEngine$$ExternalSyntheticLambda19.onValue(D8$$SyntheticClass:0)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	at org.mozilla.geckoview.GeckoResult.lambda$thenInternal$6(GeckoResult.java:593)
03-18 11:54:36.482 17377 17377 E AndroidRuntime: 	... 12 more
03-18 11:54:36.483 17377 17377 E ExceptionHandler: Uncaught exception handled: 
03-18 11:54:36.483 17377 17377 E ExceptionHandler: org.mozilla.geckoview.GeckoResult$UncaughtException: org.mozilla.experiments.nimbus.internal.InternalException: called `Option::unwrap()` on a `None` value
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at org.mozilla.geckoview.GeckoResult.dispatchLocked(GeckoResult.java:782)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at org.mozilla.geckoview.GeckoResult.completeExceptionally(GeckoResult.java:925)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at org.mozilla.geckoview.GeckoResult.lambda$thenInternal$6(GeckoResult.java:606)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at org.mozilla.geckoview.GeckoResult.$r8$lambda$82f7lYxeXTzVvMgd9wZnqr4Ug34(Unknown Source:0)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at org.mozilla.geckoview.GeckoResult$$ExternalSyntheticLambda7.run(D8$$SyntheticClass:0)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at org.mozilla.geckoview.GeckoResult.lambda$dispatchLocked$7(GeckoResult.java:797)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at org.mozilla.geckoview.GeckoResult$$ExternalSyntheticLambda8.run(D8$$SyntheticClass:0)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at android.os.Handler.handleCallback(Handler.java:958)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at android.os.Handler.dispatchMessage(Handler.java:99)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at android.os.Looper.loopOnce(Looper.java:205)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at android.os.Looper.loop(Looper.java:294)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at android.app.ActivityThread.main(ActivityThread.java:8177)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at java.lang.reflect.Method.invoke(Native Method)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:552)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:971)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: Caused by: org.mozilla.experiments.nimbus.internal.InternalException: called `Option::unwrap()` on a `None` value
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at org.mozilla.experiments.nimbus.internal.NimbusKt.uniffiCheckCallStatus(nimbus.kt:384)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at org.mozilla.experiments.nimbus.internal.NimbusKt.access$uniffiCheckCallStatus(nimbus.kt:1)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at org.mozilla.experiments.nimbus.internal.NimbusClient.unenrollForGeckoPref(nimbus.kt:3101)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at org.mozilla.experiments.nimbus.Nimbus.unenrollForGeckoPref(Nimbus.kt:461)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at org.mozilla.fenix.experiments.prefhandling.NimbusGeckoPrefHandler.handleErrors(NimbusGeckoPrefHandler.kt:171)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at org.mozilla.fenix.experiments.prefhandling.NimbusGeckoPrefHandler.applyEnrollmentPrefs$lambda$0(NimbusGeckoPrefHandler.kt:323)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at org.mozilla.fenix.experiments.prefhandling.NimbusGeckoPrefHandler.$r8$lambda$xCnViHOCuX-0NDvgsfw2YU3Up-Q(Unknown Source:0)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at org.mozilla.fenix.experiments.prefhandling.NimbusGeckoPrefHandler$$ExternalSyntheticLambda3.invoke(D8$$SyntheticClass:0)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at mozilla.components.browser.engine.gecko.GeckoEngine.setBrowserPrefs$lambda$1(GeckoEngine.kt:1300)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at mozilla.components.browser.engine.gecko.GeckoEngine.$r8$lambda$STYT63XFj_Wj9bImnp6WV-iEtJY(Unknown Source:0)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at mozilla.components.browser.engine.gecko.GeckoEngine$$ExternalSyntheticLambda19.onValue(D8$$SyntheticClass:0)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	at org.mozilla.geckoview.GeckoResult.lambda$thenInternal$6(GeckoResult.java:593)
03-18 11:54:36.483 17377 17377 E ExceptionHandler: 	... 12 more

Not sure what the idiomatic way is to just continue on in Rust. But it seems acceptable to continue, because the experiment was invalidated.

[ohall-m]

(This scenario also causes a fatal crash.)

[ohall-m]

Manually checked that the failure isn't happening anymore. (The situation that causes this should also be improved in D288972 on the Fenix side.)