The Timber (V 4.5.0) lint checks only work via Gradle (but not via the lint command and also not in Android Studio Version 2.3 Beta2).
Summary
When I run lint directly on the command line I get an error.
lint --show TimberArgCount
Could not load custom rule jar file /home/tmtron/.android/lint/timber-lint.jar
java.lang.NoClassDefFoundError: com/android/tools/lint/detector/api/Detector$JavaPsiScanner
but it works when I invoke it via gradle:
./gradlew lint
MainActivity.java:15: Error: Wrong argument count,
format string %s.%s requires 2 but format call supplies 1 [TimberArgCount]
Timber.d("%s.%s", "onCreate");
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Detailed description
I've made a small sample project on GitHub: TimberLintTest
Basically I did this:
- created a simple Android project in Android Studio
- added Timber
- activated stdout output for lint errors
android { lintOptions { textReport true textOutput "stdout" } }
In the MainActivity I use an erronous log-statement like this:
Timber.d("%s.%s", "onCreate");
When I execute lint via the Gradle-wrapper from the command line it works as expected - stripped output:
MainActivity.java:15: Error: Wrong argument count,
format string %s.%s requires 2 but format call supplies 1 [TimberArgCount]
Timber.d("%s.%s", "onCreate");
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
But the checks don't work in Android Studio and also not when I start lint directly.
Some sources in the internet indicate that we must copy the lint.jar file to ~/.android/lint. I did that for the lint.jar (from timber-4.5.0) and renamed it to timber-lint.jar, so that I end up with this file:
~/.android/lint/timber-lint.jar
So the problem is that this JavaPsiScanner interface is not found.
I have checked the Timber source code and it depends on the lint-api-25.0.2 where the Detector contains this inner interface. But in my local SDK code (Android/Sdk/tools/lib/lint-api.jar) this inner class does not exist (I guess this is what the lint command line tool and Android Studio use).
So I think it's just a version mismatch. But I am not sure how to resolve this.
How can I even know for sure, which version of lint-api.jar my current android tools have?
When start the sdk manager and it shows that the Android SDK Tools version is 25.2.5 (I've updated to the most recent version). So is this the version of the lint-api.jar (or is it the SDK platform-tools, SDK build-tools, ..)?
As a workaround we can tell gradle to always run the lint checks after compilation. Then the lint checks will also be executed after you press Build - Make Project in Android Studio, which solves my original problem.
Gradle details are in this SO-answer.