[MNG-5787] Moving from Maven 3.0.5 to 3.3.3 breaks plugins with some dependencies on the class path

[jira-importer]

Christian Schlichtherle opened MNG-5787 and commented

There is a regression when setting up the class path for a plugin in Maven 3.3.1. The following commands run fine when using Maven 3.2.5 or older:

$ mvn --version
Apache Maven 3.2.5 (12a6b3acb947671f09b81f49094c53f426d8cea1; 2014-12-14T18:29:23+01:00)
Maven home: /usr/local/Cellar/maven/3.2.5/libexec
Java version: 1.8.0_40, vendor: Oracle Corporation
Java home: /Library/Java/JavaVirtualMachines/jdk1.8.0_40.jdk/Contents/Home/jre
Default locale: de_DE, platform encoding: UTF-8
OS name: "mac os x", version: "10.10.2", arch: "x86_64", family: "mac"
$ mvn archetype:generate \
    -DarchetypeGroupId=net.java.truelicense \
    -DarchetypeArtifactId=truelicense-maven-archetype \
    -DarchetypeVersion=2.3.4 \
    -DgroupId=com.company.product \
    -DartifactId=product \
    -Dversion=0.1-SNAPSHOT \
    -Dpackage=com.company.product \
    -Dsubject="Product 1"
[...]
$ cd project
$ mvn clean install
[...]

Note that I have shortened the output using bracketed ellipsis \[...\].

However, when running the same commands using Maven 3.3.1, I get the following output:

$ mvn --version
Apache Maven 3.3.1 (cab6659f9874fa96462afef40fcf6bc033d58c1c; 2015-03-13T21:10:27+01:00)
Maven home: /Users/christian/Downloads/apache-maven-3.3.1
Java version: 1.8.0_40, vendor: Oracle Corporation
Java home: /Library/Java/JavaVirtualMachines/jdk1.8.0_40.jdk/Contents/Home/jre
Default locale: de_DE, platform encoding: UTF-8
OS name: "mac os x", version: "10.10.2", arch: "x86_64", family: "mac"
$ mvn archetype:generate \
    -DarchetypeGroupId=net.java.truelicense \
    -DarchetypeArtifactId=truelicense-maven-archetype \
    -DarchetypeVersion=2.3.4 \
    -DgroupId=com.company.product \
    -DartifactId=product \
    -Dversion=0.1-SNAPSHOT \
    -Dpackage=com.company.product \
    -Dsubject="Product 1"
[...]
$ cd project
$ mvn clean install
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Build Order:
[INFO] 
[INFO] product
[INFO] keygen
[INFO] keymgr
[INFO] keysrv
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building product 0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- maven-clean-plugin:2.6:clean (default-clean) @ product ---
[INFO] 
[INFO] --- maven-enforcer-plugin:1.3.1:enforce (enforce-maven) @ product ---
[INFO] 
[INFO] --- maven-install-plugin:2.5.2:install (default-install) @ product ---
[INFO] Installing /Users/christian/sandbox/truelicense/product/pom.xml to /Users/christian/.m2/repository/com/company/product/product/0.1-SNAPSHOT/product-0.1-SNAPSHOT.pom
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building keygen 0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- maven-clean-plugin:2.6:clean (default-clean) @ keygen ---
[INFO] Deleting /Users/christian/sandbox/truelicense/product/keygen/target
[INFO] 
[INFO] --- maven-enforcer-plugin:1.3.1:enforce (enforce-maven) @ keygen ---
[INFO] 
[INFO] --- maven-resources-plugin:2.7:resources (default-resources) @ keygen ---
[INFO] Using 'US-ASCII' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] Copying 1 resource
[INFO] 
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ keygen ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 2 source files to /Users/christian/sandbox/truelicense/product/keygen/target/classes
[INFO] 
[INFO] --- truelicense-maven-plugin:2.3.4:obfuscate (default) @ keygen ---
[INFO] Obfuscating annotated constant string values in /Users/christian/sandbox/truelicense/product/keygen/target/classes.
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO] 
[INFO] product ............................................ SUCCESS [  0.411 s]
[INFO] keygen ............................................. FAILURE [  1.022 s]
[INFO] keymgr ............................................. SKIPPED
[INFO] keysrv ............................................. SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.646 s
[INFO] Finished at: 2015-03-18T19:31:46+01:00
[INFO] Final Memory: 15M/245M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal net.java.truelicense:truelicense-maven-plugin:2.3.4:obfuscate (default) on project keygen: Execution default of goal net.java.truelicense:truelicense-maven-plugin:2.3.4:obfuscate failed: A required class was missing while executing net.java.truelicense:truelicense-maven-plugin:2.3.4:obfuscate: org/slf4j/helpers/MarkerIgnoringBase
[ERROR] -----------------------------------------------------
[ERROR] realm =    plugin>net.java.truelicense:truelicense-maven-plugin:2.3.4
[ERROR] strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy
[ERROR] urls[0] = file:/Users/christian/.m2/repository/net/java/truelicense/truelicense-maven-plugin/2.3.4/truelicense-maven-plugin-2.3.4.jar
[ERROR] urls[1] = file:/Users/christian/.m2/repository/net/java/truelicense/truelicense-obfuscate/2.3.4/truelicense-obfuscate-2.3.4.jar
[ERROR] urls[2] = file:/Users/christian/.m2/repository/de/schlichtherle/truezip/truezip-driver-zip/7.7.6/truezip-driver-zip-7.7.6.jar
[ERROR] urls[3] = file:/Users/christian/.m2/repository/de/schlichtherle/truezip/truezip-swing/7.7.6/truezip-swing-7.7.6.jar
[ERROR] urls[4] = file:/Users/christian/.m2/repository/org/apache/commons/commons-compress/1.9/commons-compress-1.9.jar
[ERROR] urls[5] = file:/Users/christian/.m2/repository/de/schlichtherle/truezip/truezip-kernel/7.7.6/truezip-kernel-7.7.6.jar
[ERROR] urls[6] = file:/Users/christian/.m2/repository/de/schlichtherle/truezip/truezip-file/7.7.6/truezip-file-7.7.6.jar
[ERROR] urls[7] = file:/Users/christian/.m2/repository/de/schlichtherle/truezip/truezip-driver-file/7.7.6/truezip-driver-file-7.7.6.jar
[ERROR] urls[8] = file:/Users/christian/.m2/repository/org/ow2/asm/asm-tree/5.0.3/asm-tree-5.0.3.jar
[ERROR] urls[9] = file:/Users/christian/.m2/repository/org/ow2/asm/asm/5.0.3/asm-5.0.3.jar
[ERROR] urls[10] = file:/Users/christian/.m2/repository/org/codehaus/plexus/plexus-utils/1.1/plexus-utils-1.1.jar
[ERROR] Number of foreign imports: 1
[ERROR] import: Entry[import  from realm ClassRealm[maven.api, parent: null]]
[ERROR] 
[ERROR] -----------------------------------------------------: org.slf4j.helpers.MarkerIgnoringBase
[ERROR] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginContainerException
[ERROR] 
[ERROR] After correcting the problems, you can resume the build with the command
[ERROR]   mvn <goals> -rf :keygen

org.slf4j.helpers.MarkerIgnoringBase is a class in the SLF4J API. Version 1.7.7 is a compile dependency of the TrueLicense Maven Plugin, as can be seen at https://repo1.maven.org/maven2/net/java/truelicense/truelicense-maven-plugin/2.3.4/truelicense-maven-plugin-2.3.4.pom , however it is apparently missing on the class path when building the project with Maven 3.3.1.

Using a 1.7 JDK makes no difference, too.

---

Affects: 3.3.1, 3.3.3

Attachments:

• hello-maven-plugin.zip (2.96 kB)

Issue Links:

• MNG-5842 java.lang.NoClassDefFoundError: org/slf4j/helpers/MessageFormatter with jetty plugin
  ("is duplicated by")
• MNG-5845 when in maven mojo, ClassNotFoundException slf4j-api MessageFormatter class
  ("is duplicated by")

14 votes, 25 watchers

[jira-importer]

velo commented

Got the same problem here, but with a different plugin:

[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Scanning: /home/velo/.m2/repository/org/projectlombok/lombok/1.14.8:/home/velo/.m2/repository/javax/javaee-api/6.0-contaazul:/home/velo/.m2/repository/com/google/guava/guava/18.0
[INFO] Total time: 13.312 s (Wall Clock)
[INFO] Finished at: 2015-03-20T16:55:08-03:00
[INFO] Final Memory: 59M/1963M
[INFO] ------------------------------------------------------------------------
[INFO] Installing /home/velo/contaazul/contaazul-app-parent/pom.xml to /home/velo/.m2/repository/com/contaazul/contaazul-app-parent/1.0-SNAPSHOT/contaazul-app-parent-1.0-SNAPSHOT.pom
[ERROR] Failed to execute goal com.github.eirslett:frontend-maven-plugin:0.0.20:install-node-and-npm (install node and npm) on project contaazul-static: Execution install node and npm of goal com.github.eirslett:frontend-maven-plugin:0.0.20:install-node-and-npm failed: A required class was missing while executing com.github.eirslett:frontend-maven-plugin:0.0.20:install-node-and-npm: org/slf4j/helpers/MarkerIgnoringBase
[ERROR] -----------------------------------------------------
[ERROR] realm =    plugin>com.github.eirslett:frontend-maven-plugin:0.0.20
[ERROR] strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy
[ERROR] urls[0] = file:/home/velo/.m2/repository/com/github/eirslett/frontend-maven-plugin/0.0.20/frontend-maven-plugin-0.0.20.jar
[ERROR] urls[1] = file:/home/velo/.m2/repository/com/github/eirslett/frontend-plugin-core/0.0.20/frontend-plugin-core-0.0.20.jar
[ERROR] urls[2] = file:/home/velo/.m2/repository/org/codehaus/jackson/jackson-mapper-asl/1.9.13/jackson-mapper-asl-1.9.13.jar
[ERROR] urls[3] = file:/home/velo/.m2/repository/org/codehaus/jackson/jackson-core-asl/1.9.13/jackson-core-asl-1.9.13.jar
[ERROR] urls[4] = file:/home/velo/.m2/repository/org/apache/commons/commons-compress/1.5/commons-compress-1.5.jar
[ERROR] urls[5] = file:/home/velo/.m2/repository/org/tukaani/xz/1.2/xz-1.2.jar
[ERROR] urls[6] = file:/home/velo/.m2/repository/commons-io/commons-io/1.3.2/commons-io-1.3.2.jar
[ERROR] urls[7] = file:/home/velo/.m2/repository/org/apache/httpcomponents/httpclient/4.3.1/httpclient-4.3.1.jar
[ERROR] urls[8] = file:/home/velo/.m2/repository/org/apache/httpcomponents/httpcore/4.3/httpcore-4.3.jar
[ERROR] urls[9] = file:/home/velo/.m2/repository/commons-logging/commons-logging/1.1.3/commons-logging-1.1.3.jar
[ERROR] urls[10] = file:/home/velo/.m2/repository/commons-codec/commons-codec/1.6/commons-codec-1.6.jar
[ERROR] urls[11] = file:/home/velo/.m2/repository/javax/enterprise/cdi-api/1.0/cdi-api-1.0.jar
[ERROR] urls[12] = file:/home/velo/.m2/repository/javax/annotation/jsr250-api/1.0/jsr250-api-1.0.jar
[ERROR] urls[13] = file:/home/velo/.m2/repository/com/google/guava/guava/10.0.1/guava-10.0.1.jar
[ERROR] urls[14] = file:/home/velo/.m2/repository/com/google/code/findbugs/jsr305/1.3.9/jsr305-1.3.9.jar
[ERROR] urls[15] = file:/home/velo/.m2/repository/org/sonatype/sisu/sisu-guice/3.1.0/sisu-guice-3.1.0-no_aop.jar
[ERROR] urls[16] = file:/home/velo/.m2/repository/aopalliance/aopalliance/1.0/aopalliance-1.0.jar
[ERROR] urls[17] = file:/home/velo/.m2/repository/org/eclipse/sisu/org.eclipse.sisu.inject/0.0.0.M2a/org.eclipse.sisu.inject-0.0.0.M2a.jar
[ERROR] urls[18] = file:/home/velo/.m2/repository/asm/asm/3.3.1/asm-3.3.1.jar
[ERROR] urls[19] = file:/home/velo/.m2/repository/org/codehaus/plexus/plexus-component-annotations/1.5.5/plexus-component-annotations-1.5.5.jar
[ERROR] urls[20] = file:/home/velo/.m2/repository/org/apache/maven/plugin-tools/maven-plugin-annotations/3.2/maven-plugin-annotations-3.2.jar
[ERROR] urls[21] = file:/home/velo/.m2/repository/com/googlecode/slf4j-maven-plugin-log/slf4j-maven-plugin-log/1.0.0/slf4j-maven-plugin-log-1.0.0.jar
[ERROR] urls[22] = file:/home/velo/.m2/repository/org/sonatype/plexus/plexus-build-api/0.0.7/plexus-build-api-0.0.7.jar
[ERROR] urls[23] = file:/home/velo/.m2/repository/org/codehaus/plexus/plexus-utils/1.5.8/plexus-utils-1.5.8.jar
[ERROR] Number of foreign imports: 1
[ERROR] import: Entry[import  from realm ClassRealm[maven.api, parent: null]]
[ERROR] 
[ERROR] -----------------------------------------------------: org.slf4j.helpers.MarkerIgnoringBase
[ERROR] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginContainerException
[ERROR] 
[ERROR] After correcting the problems, you can resume the build with the command

[jira-importer]

Roman commented

Got the same issue with Maven 3.3.1:

[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.447 s
[INFO] Finished at: 2015-03-26T10:37:00+05:00
[INFO] Final Memory: 6M/15M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal com.github.eirslett:frontend-maven-plugin:0.0.22:gulp (default-cli) on project veb-spaimip: Execution default-cli of goal com.github.eirslett:frontend-maven-plugin:0.0.22:gulp failed: A required class was missing while executing com.github.eirslett:frontend-maven-plugin:0.0.22:gulp: org/slf4j/helpers/MarkerIgnoringBase
[ERROR] -----------------------------------------------------
[ERROR] realm =    plugin>com.github.eirslett:frontend-maven-plugin:0.0.22
[ERROR] strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy
[ERROR] urls[0] = file:/D:/java/.m2/repository/com/github/eirslett/frontend-maven-plugin/0.0.22/frontend-maven-plugin-0.0.22.jar
[ERROR] urls[1] = file:/D:/java/.m2/repository/com/github/eirslett/frontend-plugin-core/0.0.22/frontend-plugin-core-0.0.22.jar
[ERROR] urls[2] = file:/D:/java/.m2/repository/org/codehaus/jackson/jackson-mapper-asl/1.9.13/jackson-mapper-asl-1.9.13.jar
[ERROR] urls[3] = file:/D:/java/.m2/repository/org/codehaus/jackson/jackson-core-asl/1.9.13/jackson-core-asl-1.9.13.jar
[ERROR] urls[4] = file:/D:/java/.m2/repository/org/apache/commons/commons-compress/1.5/commons-compress-1.5.jar
[ERROR] urls[5] = file:/D:/java/.m2/repository/org/tukaani/xz/1.2/xz-1.2.jar
[ERROR] urls[6] = file:/D:/java/.m2/repository/commons-io/commons-io/1.3.2/commons-io-1.3.2.jar
[ERROR] urls[7] = file:/D:/java/.m2/repository/org/apache/httpcomponents/httpclient/4.3.1/httpclient-4.3.1.jar
[ERROR] urls[8] = file:/D:/java/.m2/repository/org/apache/httpcomponents/httpcore/4.3/httpcore-4.3.jar
[ERROR] urls[9] = file:/D:/java/.m2/repository/commons-logging/commons-logging/1.1.3/commons-logging-1.1.3.jar
[ERROR] urls[10] = file:/D:/java/.m2/repository/commons-codec/commons-codec/1.6/commons-codec-1.6.jar
[ERROR] urls[11] = file:/D:/java/.m2/repository/javax/enterprise/cdi-api/1.0/cdi-api-1.0.jar
[ERROR] urls[12] = file:/D:/java/.m2/repository/javax/annotation/jsr250-api/1.0/jsr250-api-1.0.jar
[ERROR] urls[13] = file:/D:/java/.m2/repository/com/google/guava/guava/10.0.1/guava-10.0.1.jar
[ERROR] urls[14] = file:/D:/java/.m2/repository/com/google/code/findbugs/jsr305/1.3.9/jsr305-1.3.9.jar
[ERROR] urls[15] = file:/D:/java/.m2/repository/org/sonatype/sisu/sisu-guice/3.1.0/sisu-guice-3.1.0-no_aop.jar
[ERROR] urls[16] = file:/D:/java/.m2/repository/aopalliance/aopalliance/1.0/aopalliance-1.0.jar
[ERROR] urls[17] = file:/D:/java/.m2/repository/org/eclipse/sisu/org.eclipse.sisu.inject/0.0.0.M2a/org.eclipse.sisu.inject-0.0.0.M2a.jar
[ERROR] urls[18] = file:/D:/java/.m2/repository/asm/asm/3.3.1/asm-3.3.1.jar
[ERROR] urls[19] = file:/D:/java/.m2/repository/org/codehaus/plexus/plexus-component-annotations/1.5.5/plexus-component-annotations-1.5.5.jar
[ERROR] urls[20] = file:/D:/java/.m2/repository/org/apache/maven/plugin-tools/maven-plugin-annotations/3.2/maven-plugin-annotations-3.2.jar
[ERROR] urls[21] = file:/D:/java/.m2/repository/com/googlecode/slf4j-maven-plugin-log/slf4j-maven-plugin-log/1.0.0/slf4j-maven-plugin-log-1.0.0.jar
[ERROR] urls[22] = file:/D:/java/.m2/repository/org/sonatype/plexus/plexus-build-api/0.0.7/plexus-build-api-0.0.7.jar
[ERROR] urls[23] = file:/D:/java/.m2/repository/org/codehaus/plexus/plexus-utils/1.5.8/plexus-utils-1.5.8.jar
[ERROR] Number of foreign imports: 1
[ERROR] import: Entry[import  from realm ClassRealm[maven.api, parent: null]]
[ERROR] 
[ERROR] -----------------------------------------------------: org.slf4j.helpers.MarkerIgnoringBase
[ERROR] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginContainerException

[jira-importer]

Dan Tran commented

frontend-maven-plugin fixed this issue eirslett/frontend-maven-plugin#178

[jira-importer]

Christian Schlichtherle commented

@Dan Tran: Thanks for the hint. I have inspected the patch, but this isn't really a fix. At best, it's a workaround which I suspect to break on any other use of the SLF4J API in the plugin.

I have investigated the case and prepared a very simple test plugin (only 3 files) which runs fine with Maven 3.2.5, but breaks with Maven 3.3.1 - see attached ZIP file. The archive contains the following files:

• pom.xml: Copied from http://maven.apache.org/guides/plugin/guide-java-plugin-development.html and added a dependency on the SLF4J API version 1.7.5. This is the same version as the one that ships with Maven 3.3.1.
• src/main/java/sample/plugin.LoggerAdapter.java: Extends org.slf4j.helpers.MarkerIgnoringBase and adapts it to org.apache.maven.plugin.logging.Log. I need this class in my TrueLicense Maven Plugin.
• src/main/java/sample/plugin/GreetingMojo.java: Copied from the same page and edited it to use the LoggerAdapter class.

After building the plugin, I can run its MOJO using Maven 3.2.5 just fine:

$ M2_HOME=/usr/local/Cellar/maven/3.2.5/libexec mvn sample.plugin:hello-maven-plugin:1.0-SNAPSHOT:sayhi -e
[INFO] Error stacktraces are turned on.
[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building Maven Stub Project (No POM) 1
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- hello-maven-plugin:1.0-SNAPSHOT:sayhi (default-cli) @ standalone-pom ---
[INFO] Hello, world.
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.134 s
[INFO] Finished at: 2015-03-26T15:27:04+01:00
[INFO] Final Memory: 8M/309M
[INFO] ------------------------------------------------------------------------

Now using Maven 3.3.1, I get the following error message:

$ M2_HOME=/usr/local/Cellar/maven/3.3.1/libexec mvn sample.plugin:hello-maven-plugin:1.0-SNAPSHOT:sayhi -e
[INFO] Error stacktraces are turned on.
[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building Maven Stub Project (No POM) 1
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- hello-maven-plugin:1.0-SNAPSHOT:sayhi (default-cli) @ standalone-pom ---
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.126 s
[INFO] Finished at: 2015-03-26T15:27:48+01:00
[INFO] Final Memory: 8M/309M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal sample.plugin:hello-maven-plugin:1.0-SNAPSHOT:sayhi (default-cli) on project standalone-pom: Execution default-cli of goal sample.plugin:hello-maven-plugin:1.0-SNAPSHOT:sayhi failed: A required class was missing while executing sample.plugin:hello-maven-plugin:1.0-SNAPSHOT:sayhi: org/slf4j/helpers/MarkerIgnoringBase
[ERROR] -----------------------------------------------------
[ERROR] realm =    plugin>sample.plugin:hello-maven-plugin:1.0-SNAPSHOT
[ERROR] strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy
[ERROR] urls[0] = file:/Users/christian/.m2/repository/sample/plugin/hello-maven-plugin/1.0-SNAPSHOT/hello-maven-plugin-1.0-SNAPSHOT.jar
[ERROR] urls[1] = file:/Users/christian/.m2/repository/org/codehaus/plexus/plexus-utils/1.1/plexus-utils-1.1.jar
[ERROR] Number of foreign imports: 1
[ERROR] import: Entry[import  from realm ClassRealm[maven.api, parent: null]]
[ERROR] 
[ERROR] -----------------------------------------------------: org.slf4j.helpers.MarkerIgnoringBase
[ERROR] -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal sample.plugin:hello-maven-plugin:1.0-SNAPSHOT:sayhi (default-cli) on project standalone-pom: Execution default-cli of goal sample.plugin:hello-maven-plugin:1.0-SNAPSHOT:sayhi failed: A required class was missing while executing sample.plugin:hello-maven-plugin:1.0-SNAPSHOT:sayhi: org/slf4j/helpers/MarkerIgnoringBase
-----------------------------------------------------
realm =    plugin>sample.plugin:hello-maven-plugin:1.0-SNAPSHOT
strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy
urls[0] = file:/Users/christian/.m2/repository/sample/plugin/hello-maven-plugin/1.0-SNAPSHOT/hello-maven-plugin-1.0-SNAPSHOT.jar
urls[1] = file:/Users/christian/.m2/repository/org/codehaus/plexus/plexus-utils/1.1/plexus-utils-1.1.jar
Number of foreign imports: 1
import: Entry[import  from realm ClassRealm[maven.api, parent: null]]

-----------------------------------------------------

	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:224)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
	at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
	at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
	at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
	at org.apache.maven.cli.MavenCli.execute(MavenCli.java:862)
	at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:286)
	at org.apache.maven.cli.MavenCli.main(MavenCli.java:197)
	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:497)
	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: org.apache.maven.plugin.PluginExecutionException: Execution default-cli of goal sample.plugin:hello-maven-plugin:1.0-SNAPSHOT:sayhi failed: A required class was missing while executing sample.plugin:hello-maven-plugin:1.0-SNAPSHOT:sayhi: org/slf4j/helpers/MarkerIgnoringBase
-----------------------------------------------------
realm =    plugin>sample.plugin:hello-maven-plugin:1.0-SNAPSHOT
strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy
urls[0] = file:/Users/christian/.m2/repository/sample/plugin/hello-maven-plugin/1.0-SNAPSHOT/hello-maven-plugin-1.0-SNAPSHOT.jar
urls[1] = file:/Users/christian/.m2/repository/org/codehaus/plexus/plexus-utils/1.1/plexus-utils-1.1.jar
Number of foreign imports: 1
import: Entry[import  from realm ClassRealm[maven.api, parent: null]]

-----------------------------------------------------

	at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:168)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
	... 20 more
Caused by: org.apache.maven.plugin.PluginContainerException: A required class was missing while executing sample.plugin:hello-maven-plugin:1.0-SNAPSHOT:sayhi: org/slf4j/helpers/MarkerIgnoringBase
-----------------------------------------------------
realm =    plugin>sample.plugin:hello-maven-plugin:1.0-SNAPSHOT
strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy
urls[0] = file:/Users/christian/.m2/repository/sample/plugin/hello-maven-plugin/1.0-SNAPSHOT/hello-maven-plugin-1.0-SNAPSHOT.jar
urls[1] = file:/Users/christian/.m2/repository/org/codehaus/plexus/plexus-utils/1.1/plexus-utils-1.1.jar
Number of foreign imports: 1
import: Entry[import  from realm ClassRealm[maven.api, parent: null]]

-----------------------------------------------------

	at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:166)
	... 21 more
Caused by: java.lang.NoClassDefFoundError: org/slf4j/helpers/MarkerIgnoringBase
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:760)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
	at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
	at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClassFromSelf(ClassRealm.java:401)
	at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:42)
	at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass(ClassRealm.java:271)
	at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:247)
	at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:239)
	at sample.plugin.GreetingMojo.execute(GreetingMojo.java:10)
	at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
	... 21 more
Caused by: java.lang.ClassNotFoundException: org.slf4j.helpers.MarkerIgnoringBase
	at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:50)
	at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass(ClassRealm.java:271)
	at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:247)
	at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:239)
	... 37 more
[ERROR] 
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginContainerException

This is becoming a critical issue for me. Any help is greatly appreciated.

[jira-importer]

Christian Schlichtherle commented

Here is an effective work-around: Add the maven-shade-plugin to the plugin POM and make sure to declare the scope of the maven-plugin-annotations and the maven-plugin-api as provided. The maven-shade-plugin creates an Uber JAR for the plugin which includes the slf4j-api. This runs fine with both Maven 3.3.1 and Maven 3.2.5.

[jira-importer]

Christian Schlichtherle commented

It happened to me today again. This time another class from another dependency could not be found on the class path, although it was definitely present. I presume something is not right with the Classworlds component when there are many dependencies.

[jira-importer]

S L commented

Christian Schlichtherle Thanks for the Tip with jaring the slfj4 in the plugin (by using the maven-shade-plugin).
We ran into the sample Problem and since our Plugin somehow needs to have support for -Dorg.slf4j.simpleLogger.defaultLogLevel=warn we have to include the slfj4-implementation in our plugin.
The Workaround suggested from Dan Tran ignores this Environment-Settings.
However, I just filed this as an additional Bug (MNG-5835).

[jira-importer]

Andreas Horst commented

I just ran into this with 3.3.3 today. What I really don't understand is that slf4j-api is listed in the dependency collection stats for the affected plugin but later on in the populated class realm it's missing.

[jira-importer]

Fabian Kürten commented

This also affects the maven-antrun-plugin both with 3.3.1 and 3.3.3 when trying to use the cobertura ant task.
pluginArtifacts contains slf4j-api but the actual java call from ant to cobertura specifies a classpath without slf4j.