Basic maven plugin project not working, Mojo plugin descriptors not generating

Question

I am following the tutorial for creating a maven plugin and cannot run mvn install without getting errors. The info complains that i don't have the required mojo descriptors when the annotations should be generating them for me. I am running maven 3.0.5 and using intellij as my ide. here is my Main class:

@Mojo(name = "modify-connector") public class ComplianceMojo extends AbstractMojo {      @Parameter     private String artifactId;      @Parameter     private String version;      @Override     public void execute() throws MojoExecutionException, MojoFailureException {         File jar = new File(getPluginContext().get("project.build.directory") + "/"                 + getPluginContext().get("project.build.finalname") + "/" + artifactId + "-" + version);         if(jar.exists()){             getLog().info("The file exists! " + jar.getAbsolutePath());         } else {             getLog().info("The file does not exist: " + jar.getAbsolutePath());         }     } } 

And here is my pom.xml

<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0"          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">     <modelVersion>4.0.0</modelVersion>      <groupId>mysql-jdbc-compliance-maven-plugin</groupId>     <artifactId>mysql-jdbc-compliance-maven-plugin</artifactId>     <version>1.0-SNAPSHOT</version>     <packaging>maven-plugin</packaging>      <dependencies>         <dependency>             <groupId>org.apache.maven</groupId>             <artifactId>maven-plugin-api</artifactId>             <version>2.0</version>         </dependency>         <dependency>             <groupId>org.apache.maven.plugin-tools</groupId>             <artifactId>maven-plugin-annotations</artifactId>             <version>3.2</version>             <scope>provided</scope>         </dependency>     </dependencies>  </project> 

Note: I had to separately add the annotations dependency as the main plugin api did not contain these classes. when i run mvn install on my project, the output is as follows:

[INFO] ------------------------------------------------------------------------ [INFO] BUILD FAILURE [INFO] ------------------------------------------------------------------------ [INFO] Total time: 0.867s [INFO] Finished at: Wed Sep 25 17:45:55 EST 2013 [INFO] Final Memory: 8M/244M [INFO] ------------------------------------------------------------------------ [ERROR] Failed to execute goal org.apache.maven.plugins:maven-plugin-plugin:2.9:descriptor (default-descriptor) on project mysql-jdbc-compliance-maven-plugin: Error extracting plugin descriptor: 'No mojo definitions were found for plugin: mysql-jdbc-compliance-maven-plugin:mysql-jdbc-compliance-maven-plugin.' -> [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/MojoExecutionException 

Answer 1

Maybe this is related to a unresolved issue in Maven: https://issues.apache.org/jira/browse/MNG-5346

For my plugin projects, i could workaround by adding an explicit execution of the maven-plugin-plugin:

<build>         <plugins>             <plugin>                 <groupId>org.apache.maven.plugins</groupId>                 <artifactId>maven-plugin-plugin</artifactId>                 <version>3.2</version>                 <configuration>                     <!-- see http://jira.codehaus.org/browse/MNG-5346 -->                     <skipErrorNoDescriptorsFound>true</skipErrorNoDescriptorsFound>                 </configuration>                  <executions>                     <execution>                         <id>mojo-descriptor</id>                         <goals>                             <goal>descriptor</goal>                         </goals>                     </execution>                 </executions>             </plugin>         </plugins>     </build> 

But see the comments in the JIRA issue for more elaborate solutions!