[FELIX-6023] SCR bnd plugin sometimes fails with IncompatibleClassChangeError: Implementing class

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: scr bnd plugin 1.9.0
• Fix Version/s: scr bnd plugin 1.9.2
• Component/s: SCR Tooling
• Labels: patch-available

Environment

Maven home: /usr/local/Cellar/maven/3.6.0/libexec
Java version: 1.8.0_192, vendor: Oracle Corporation, runtime: /Library/Java/JavaVirtualMachines/jdk1.8.0_192.jdk/Contents/Home/jre
Default locale: en_US, platform encoding: UTF-8
OS name: "mac os x", version: "10.14.2", arch: "x86_64", family: "mac"

• Assignee: Stefan Seifert
• Reporter: Mark Adamcin
• Created: 10/Jan/19 20:28
• Updated: 26/Jan/19 11:07
• Resolved: 17/Jan/19 08:53

Description

 

When building a project where a newer version of a dependency is embedded in the project artifact with a conflicting older version of said dependency is also present on the classpath, SOME environments encounter an exception that is similar to the following:

[ERROR] Manifest com.adobe.acs:acs-aem-commons-bundle:bundle:3.19.1-SNAPSHOT : Got unexpected exception while analyzing:org.apache.felix.scrplugin.SCRDescriptorException: Unable to load compiled class: com.google.common.base.Suppliers$SupplierFunctionImpl
	at org.apache.felix.scrplugin.helper.ClassScanner.scanSources(ClassScanner.java:156)
	at org.apache.felix.scrplugin.SCRDescriptorGenerator.execute(SCRDescriptorGenerator.java:146)
	at org.apache.felix.scrplugin.bnd.SCRDescriptorBndPlugin.analyzeJar(SCRDescriptorBndPlugin.java:178)
	at aQute.bnd.osgi.Analyzer.doPlugins(Analyzer.java:820)
	at aQute.bnd.osgi.Analyzer.analyze(Analyzer.java:229)
	at aQute.bnd.osgi.Builder.analyze(Builder.java:408)
	at aQute.bnd.osgi.Analyzer.calcManifest(Analyzer.java:850)
	at aQute.bnd.osgi.Builder.build(Builder.java:116)
	at org.apache.felix.bundleplugin.ManifestPlugin.getAnalyzer(ManifestPlugin.java:291)
	at org.apache.felix.bundleplugin.ManifestPlugin.execute(ManifestPlugin.java:98)
	at org.apache.felix.bundleplugin.BundlePlugin.execute(BundlePlugin.java:384)
	at org.apache.felix.bundleplugin.BundlePlugin.execute(BundlePlugin.java:375)
	at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:137)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:210)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:156)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:148)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:117)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:81)
	at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:56)
	at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:305)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:192)
	at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:105)
	at org.apache.maven.cli.MavenCli.execute(MavenCli.java:956)
	at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
	at org.apache.maven.cli.MavenCli.main(MavenCli.java:192)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
	at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
	at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: java.lang.IncompatibleClassChangeError: Implementing class
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:468)
	at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:363)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:362)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	at org.apache.felix.scrplugin.helper.ClassScanner.scanSources(ClassScanner.java:144)
	... 33 more

[ERROR] Error(s) found in manifest configuration

The sequence of dependencies in the build should allow the preferred embedded version to be declared with higher precedence than the non-preferred version, but this sequence does not appear to be respected because of the use of a non-linked HashSet in `SCRDescriptorBndPlugin.getClassPath()` to post-process the list of classpath elements returned from Analyzer.getClasspath().

I attached to debug logs from the execution. the *.bnd-1.9.0.log file shows the `uber-jar` artifact listed before the `guava` artifact in the classpath log, but their order is reversed in the dependencies log.

I then replaced the HashSet with a LinkedHashSet in the bnd plugin and rebuilt the project, resulting in the *.bnd-1.9.1-SNAPSHOT.log, which shows the sequence of these two artifacts being the same in both the classpath log and the dependencies log.

See: https://github.com/Adobe-Consulting-Services/acs-aem-commons/issues/1675 for background.

Issue Links

• links to: GitHub Pull Request #165
• links to: GitHub Pull Request #165