Can't Create Logger: DateTokenConverter not found?

[davidvedvick]

Describe the bug

After upgrading the Android Gradle Plugin to 8.0, my application crashes. Logs indicate that this is because I have an invalid date token, but the date token appears correct.

java.lang.RuntimeException: Unable to create application com.lasthopesoftware.bluewater.MainApplication: java.lang.IllegalStateException: FileNamePattern [/storage/emulated/0/Android/data/com.lasthopesoftware.bluewater/files/logs/%d{yyyy-MM-dd}.log] does not contain a valid DateToken

Issue starts occurring in this commit:

namehillsoftware/projectBlue@76e9c64

and is worked around by this commit:

namehillsoftware/projectBlue@6d4def3

Updating the proguard file to avoid DateTokenConverter (and other converters perhaps) seemed to fix it:

-keepclassmembers class ch.qos.logback.core.rolling.helper.* { <init>(); }

Reproduction

namehillsoftware/projectBlue@76e9c64

Logs

No response

logback-android version

3.0.0, 2.0.0

OS Version

Android 13

What logback configuration are you using? (logback.xml or Java/Kotlin code)

Kotlin code

Validations

• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A, please open a GitHub Discussion instead.
• The provided reproduction is a minimal reproducible of the bug.

[noproxy]

It affects all logback-android versions.

AGP enables R8 full mode by default since 8.0.0.

And the R8 full mode has some behaviors difference, and the relevant change is:

The default constructor (<init>()) is not implicitly kept when a class is kept.

[noproxy]

It can be resolved by embedding a consumer-proguard-rules to logback-android.

defaultConfig {
      .....
      consumerProguardFiles ‘consumer-rules.pro’
}

The ‘consumer-rules.pro’ content is just as the workaround mentioned by @davidvedvick

[tony19]

Your diagnosis was exactly right — R8 strips DateTokenConverter (and the other rolling helpers) because FileNamePattern resolves %d/%i through a class-name map that R8 can't trace, and AGP 8.0 made release minification more aggressive by default. As of #418 (merged), the library ships consumer ProGuard rules inside the AAR via consumerProguardFiles, so starting with the next release no hand-written keep rules are needed. Until then your workaround stands (a -keep class ch.qos.logback.core.rolling.helper.* { *; } variant, or broader -keep class ch.qos.logback.** { *; }). Thanks for tracing it down to the exact commit and sharing the fix!

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