IssueTracker

The most common devices for the first crash sorted from highest to lowest:
Samsung S8 (5% of all crashes), S9 (4%), S8+ (4%), S10+ (3%), S9+ (3%), Huawei P20 Pro & Lite (9%)

The most common devices for the second crash:
HUAWEI Y6 2019 (38% of all crashes), HUAWEI Y5 2019 (17%), Nokia 3 (10%), Nokia 2.1 (9 %), Oppo realme 1 (5%)

The most common devices for the third crash:
Samsung Galaxy A5 (14% of all crashes). S7 Edge (9%), Spa Condor Electronics PGN610 (17% of all crashes)

Crash 3 is a dupe of issue 138825362

Which library version are you using?

yeap, at least #1 was reported against the alpha here: https://stackoverflow.com/q/56358422/270197 - while the lib is now in beta

#1 and #3 are definitely fixable in the support library. #2 can likely be resolved by the app checking BiometricManager#canAuthenticate() before requesting BiometricPrompt#authenticate().

For #1)
Looks like somehow the app is trying to display the dialog after onSaveInstanceState(), e.g. the activity/fragment is ending its lifecycle? Curtis perhaps we should do some lifecycle checks here.

For #2)
tranced.freak@ do you happen to know which devices are reporting this?
There is a chance the following is happening:
  - device does not have fingerprint hardware
  - app requests authenticate()
  - hasSystemFeature(FP) fails, but invokes sendError
  - sendError needs FPM to get error string.
A solution on the app side is to check BiometricManager#canAuthenticate() before requesting authentication. Is this something the app is already doing? We will focus this bug on #1 and #3 until we hear otherwise.

For #3)
Similar onSaveInstanceState issue

Edit, just read comment #2. Y5, Nokia 3, Nokia 2.1, Realme1 don't have fingerprint sensors.

The only other device, Y6 does have a fingerprint sensor but it's possible the only other device (Y6) did not declare FEATURE_FINGERPRINT.

Either way, checking androidx.BiometricManager#canAuthenticate (added in beta01) will resolve this issue.

Project: platform/frameworks/support
Branch: androidx-master-dev

commit 549dceb1f3104bc4c4cb3e5168114f99e84a223c
Author: Curtis Belmonte <curtislb@google.com>
Date:   Tue Sep 17 11:24:07 2019

    Fix biometric dialog crashes due to state loss
   
    Making fragment transactions such as adding or removing dialogs after
    the host activity's state has been saved is currently causing crashes in
    the biometric library. normally For multiple reasons (outlined in
    b/138825362), allowing these dialogs to be dismissed with state loss is
    probably preferable anyway, so this commit makes that change. It also
    tries to prevent BiometricPrompt from triggering authentication in the
    first place if the host's state has already been saved.
   
    Test: ./gradlew biometric:connectedAndroidTest
    Test: Trigger delayed dismissal of dialog and quickly finish activity
    Test: Enable "Don't Keep Activities", show prompt and back out
    periodically
   
    Before: App crashes
    After: App no longer crashes
   
    Fixes: 138825362
    Bug: 140447194
    Change-Id: Ic2cf512c9441c2c8b83a051ff788210ae10d64b1

M       biometric/src/main/java/androidx/biometric/BiometricPrompt.java
M       biometric/src/main/java/androidx/biometric/FingerprintDialogFragment.java

https://android-review.googlesource.com/1122833
https://goto.google.com/android-sha1/549dceb1f3104bc4c4cb3e5168114f99e84a223c

are these fixes released in beta02?

> are these fixes released in beta02?

Unfortunately no, but fixes for (1) and (3) from comment #2 will be in rc01, which should be released very soon. :-)

As kchyn@google.com said, an app-side solution is probably most appropriate for (2).