CLASS_NOT_FOUND after upgrading to com.rollbar:rollbar-log4j2:1.7.3

[st-h]

After upgrading to rollbar-log4j2:1.7.3 log4j stops working and the following trace is printed to stderr

2020-07-13 21:27:02,393 main ERROR Error processing element Rollbar: CLASS_NOT_FOUND
2020-07-13 21:27:02,396 main ERROR Unable to locate plugin type for Rollbar
2020-07-13 21:27:02,459 main ERROR Unable to locate plugin for Rollbar
2020-07-13 21:27:02,461 main ERROR Unable to invoke factory method in class org.apache.logging.log4j.core.config.AppendersPlugin for element appenders: java.lang.NullPointerException java.lang.NullPointerException
#011at org.apache.logging.log4j.core.config.plugins.visitors.PluginElementVisitor.visit(PluginElementVisitor.java:52)
#011at org.apache.logging.log4j.core.config.plugins.util.PluginBuilder.generateParameters(PluginBuilder.java:258)
#011at org.apache.logging.log4j.core.config.plugins.util.PluginBuilder.build(PluginBuilder.java:135)
#011at org.apache.logging.log4j.core.config.AbstractConfiguration.createPluginObject(AbstractConfiguration.java:1002)
#011at org.apache.logging.log4j.core.config.AbstractConfiguration.createConfiguration(AbstractConfiguration.java:942)
#011at org.apache.logging.log4j.core.config.AbstractConfiguration.doConfigure(AbstractConfiguration.java:552)
#011at org.apache.logging.log4j.core.config.AbstractConfiguration.initialize(AbstractConfiguration.java:241)
#011at org.apache.logging.log4j.core.config.AbstractConfiguration.start(AbstractConfiguration.java:288)
#011at org.apache.logging.log4j.core.LoggerContext.setConfiguration(LoggerContext.java:618)
#011at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:691)
#011at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:708)
#011at org.apache.logging.log4j.core.LoggerContext.start(LoggerContext.java:263)
#011at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:243)
#011at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:45)
#011at org.apache.logging.log4j.LogManager.getContext(LogManager.java:174)
#011at org.apache.logging.log4j.LogManager.getLogger(LogManager.java:669)
#011at io.vertx.core.logging.Log4j2LogDelegate.<init>(Log4j2LogDelegate.java:31)
#011at io.vertx.core.logging.Log4j2LogDelegateFactory.createDelegate(Log4j2LogDelegateFactory.java:28)
#011at io.vertx.core.logging.LoggerFactory.getLogger(LoggerFactory.java:74)
#011at io.vertx.core.logging.LoggerFactory.getLogger(LoggerFactory.java:67)
#011at io.vertx.core.impl.launcher.commands.ClasspathHandler.<init>(ClasspathHandler.java:45)
#011at io.vertx.core.impl.launcher.commands.BareCommand.<init>(BareCommand.java:49)
#011at io.vertx.core.impl.launcher.commands.RunCommand.<init>(RunCommand.java:39)
#011at io.vertx.core.spi.launcher.DefaultCommandFactory.create(DefaultCommandFactory.java:60)
#011at io.vertx.core.impl.launcher.VertxCommandLauncher.getNewCommandInstance(VertxCommandLauncher.java:179)
#011at io.vertx.core.impl.launcher.VertxCommandLauncher.execute(VertxCommandLauncher.java:234)
#011at io.vertx.core.impl.launcher.VertxCommandLauncher.dispatch(VertxCommandLauncher.java:383)
#011at io.vertx.core.impl.launcher.VertxCommandLauncher.dispatch(VertxCommandLauncher.java:346)
#011at io.vertx.core.impl.launcher.VertxCommandLauncher$dispatch.call(Unknown Source)
#011at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47)
#011at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:125)
#011at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:139)
#011at Launcher.main(Launcher.groovy:18)

log4j version: 2.13.3
Suspecting this is related to the upgrade to Gradle 6. Our build still uses Gradle 5.6.4. Downgrading to 1.7.2 resolves the issue. Unfortunately I can not easily upgrade our deployment to Gradle 6, as it is not (yet) available within our build pipeline.

As the upgrade has been to a patch version, I wouldn't expect any breaking changes. Are you possibly aware of similar issues?

[basoko]

Hi @st-h,

I'm sorry you faced this issue, we were not aware it. Seems that after upgrading to Gradle 6 the log4j2 annotation processor was not executed and as a result of it the Log4j2Plugins.dat file was not generated.

I've merged a change that should fix the issue, could you please try with the com.rollbar:rollbar-log4j2:1.7.4-SNAPSHOT version to see if that fixes your issue? If you confirm it, I can release a new version to solve this.

Thanks!

[st-h]

@basoko thanks for the prompt response and explanation. I just tried and 1.7.4-SNAPSHOT seems to work fine 👍

[basoko]

@st-h Thanks for verifying it!

We've released the com.rollbar:rollbar-log4j2:1.7.4.