AssertionError crash on startup in PlumberInstaller

[dbrant]

I'm seeing a crash upon startup, which seems to be internal to the plumber component:

java.lang.AssertionError: impossible
        at java.lang.Enum$1.create(Enum.java:269)
        at java.lang.Enum$1.create(Enum.java:260)
        at libcore.util.BasicLruCache.get(BasicLruCache.java:58)
        at java.lang.Enum.getSharedConstants(Enum.java:286)
        at java.lang.Class.getEnumConstantsShared(Class.java:2291)
        at java.lang.JavaLangAccess.getEnumConstantsShared(JavaLangAccess.java:40)
        at java.util.EnumSet.getUniverse(EnumSet.java:389)
        at java.util.EnumSet.noneOf(EnumSet.java:107)
        at java.util.EnumSet.allOf(EnumSet.java:126)
        at leakcanary.AndroidLeakFixes$Companion.applyFixes$default(AndroidLeakFixes.kt:1)
        at leakcanary.internal.PlumberInstaller.onCreate(PlumberInstaller.kt:2)
        at android.content.ContentProvider.attachInfo(ContentProvider.java:1751)
        at android.content.ContentProvider.attachInfo(ContentProvider.java:1726)
        at android.app.ActivityThread.installProvider(ActivityThread.java:5811)
        at android.app.ActivityThread.installContentProviders(ActivityThread.java:5403)
        at android.app.ActivityThread.handleBindApplication(ActivityThread.java:5342)
        at android.app.ActivityThread.-wrap2(ActivityThread.java)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1528)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6077)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
     Caused by: java.lang.NoSuchMethodException: values []
        at java.lang.Class.getMethod(Class.java:1981)
        at java.lang.Class.getDeclaredMethod(Class.java:1960)
        at java.lang.Enum$1.create(Enum.java:265)
        at java.lang.Enum$1.create(Enum.java:260) 
        at libcore.util.BasicLruCache.get(BasicLruCache.java:58) 
        at java.lang.Enum.getSharedConstants(Enum.java:286) 
        at java.lang.Class.getEnumConstantsShared(Class.java:2291) 
        at java.lang.JavaLangAccess.getEnumConstantsShared(JavaLangAccess.java:40) 
        at java.util.EnumSet.getUniverse(EnumSet.java:389) 
        at java.util.EnumSet.noneOf(EnumSet.java:107) 
        at java.util.EnumSet.allOf(EnumSet.java:126) 
        at leakcanary.AndroidLeakFixes$Companion.applyFixes$default(AndroidLeakFixes.kt:1) 
        at leakcanary.internal.PlumberInstaller.onCreate(PlumberInstaller.kt:2) 
        at android.content.ContentProvider.attachInfo(ContentProvider.java:1751) 
        at android.content.ContentProvider.attachInfo(ContentProvider.java:1726) 
        at android.app.ActivityThread.installProvider(ActivityThread.java:5811) 
        at android.app.ActivityThread.installContentProviders(ActivityThread.java:5403) 
        at android.app.ActivityThread.handleBindApplication(ActivityThread.java:5342) 
        at android.app.ActivityThread.-wrap2(ActivityThread.java) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1528) 
        at android.os.Handler.dispatchMessage(Handler.java:102) 
        at android.os.Looper.loop(Looper.java:154) 
        at android.app.ActivityThread.main(ActivityThread.java:6077) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756) 

I was able to resolve it by including the following in my ProGuard rules:

-keepclassmembers enum * {
public static **[] values();
public static ** valueOf(java.lang.String);
}

Is it known that these rules are required, or am I doing something wrong myself?

Version Information

• LeakCanary version: 2.4
• Android OS version: tested on API 24 and 29
• Gradle version: 4.0.1

[pyricau]

Thanks for the bug report and suggested fix! Definitely not a known issue.

I haven't been able to repro, can you share a sample project or specific about the proguard config that make this happen?

Alternatively, can you try with this more specific configuration and confirm it still works:

# https://www.guardsquare.com/en/products/proguard/manual/examples#enumerations
-keep public enum leakcanary.AndroidLeakFixes {
  public static **[] values();
  public static ** valueOf(java.lang.String);
}

I've added that to https://github.com/square/leakcanary/pull/1914/files

The reason I want the more specific configuration is because apps using proguard probably still want to shrink most of their enums.

[dbrant]

Well this is odd, I can't repro this behavior now either, even on the exact commit where I observed it before. I suppose this can now be closed, and we can revisit if it's observed again.

BTW we've been using LeakCanary in the official Wikipedia app, and have found it immensely useful. Thanks!

[pyricau]

Thx! Feel free to reopen or open a new one if this happens again.

I'm glad it's useful! We have the guest book for testimonials ;)

[cooltey]

Seen this issue today and resolved it by restarting PC, invalidating Android Studio cached and checking out commits back and forth.

[jacob-peterson-zz]

I also ran into this issue after adding Plumber to release builds of my app. Others on my team could reproduce it as well but I was unable to repro it in a sample app with a similar configuration.

• LeakCanary version: 2.6
• Gradle version: 4.1.1

[jzbrooks]

Here's a sample project that reproduces the issue. The linked PR would appropriately address the issue.

leakcanaryr8.zip