command failed ./mvnw -X clean package

[polakovi]

I ran ./mvnw -X clean package following the instructions provided and received the following error message.

[DEBUG] incrementalBuildHelper#beforeRebuildExecution
[INFO] Compiling 6 source files to /home/sample/work/github.com/inventage/keycloak-custom/extensions/extension-no-op-authenticator/target/classes
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary for parent 1.0.0-SNAPSHOT:
[INFO] 
[INFO] parent ............................................. SUCCESS [  0.532 s]
[INFO] server ............................................. SUCCESS [  4.437 s]
[INFO] config ............................................. SUCCESS [  3.069 s]
[INFO] extensions ......................................... SUCCESS [  0.090 s]
[INFO] extension-no-op-authenticator ...................... FAILURE [  0.733 s]
[INFO] extension-no-op-protocol-mapper .................... SKIPPED
[INFO] themes ............................................. SKIPPED
[INFO] container .......................................... SKIPPED
[INFO] docker-compose ..................................... SKIPPED
[INFO] helm ............................................... SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  9.401 s
[INFO] Finished at: 2025-02-01T17:44:06+01:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project extension-no-op-authenticator: Fatal error compiling: error: release version 21 not supported -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project extension-no-op-authenticator: Fatal error compiling
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:215)
    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:957)
    at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:289)
    at org.apache.maven.cli.MavenCli.main (MavenCli.java:193)
    at jdk.internal.reflect.DirectMethodHandleAccessor.invoke (DirectMethodHandleAccessor.java:103)
    at java.lang.reflect.Method.invoke (Method.java:580)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:282)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:225)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:406)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:347)
    at jdk.internal.reflect.DirectMethodHandleAccessor.invoke (DirectMethodHandleAccessor.java:103)
    at java.lang.reflect.Method.invoke (Method.java:580)
    at org.apache.maven.wrapper.BootstrapMainStarter.start (BootstrapMainStarter.java:39)
    at org.apache.maven.wrapper.WrapperExecutor.execute (WrapperExecutor.java:122)
    at org.apache.maven.wrapper.MavenWrapperMain.main (MavenWrapperMain.java:61)
Caused by: org.apache.maven.plugin.MojoExecutionException: Fatal error compiling
    at org.apache.maven.plugin.compiler.AbstractCompilerMojo.execute (AbstractCompilerMojo.java:1145)
    at org.apache.maven.plugin.compiler.CompilerMojo.execute (CompilerMojo.java:187)
    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:957)
    at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:289)
    at org.apache.maven.cli.MavenCli.main (MavenCli.java:193)
    at jdk.internal.reflect.DirectMethodHandleAccessor.invoke (DirectMethodHandleAccessor.java:103)
    at java.lang.reflect.Method.invoke (Method.java:580)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:282)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:225)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:406)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:347)
    at jdk.internal.reflect.DirectMethodHandleAccessor.invoke (DirectMethodHandleAccessor.java:103)
    at java.lang.reflect.Method.invoke (Method.java:580)
    at org.apache.maven.wrapper.BootstrapMainStarter.start (BootstrapMainStarter.java:39)
    at org.apache.maven.wrapper.WrapperExecutor.execute (WrapperExecutor.java:122)
    at org.apache.maven.wrapper.MavenWrapperMain.main (MavenWrapperMain.java:61)
Caused by: org.codehaus.plexus.compiler.CompilerException: error: release version 21 not supported

$ java -version
openjdk version "21.0.6" 2025-01-21 LTS
OpenJDK Runtime Environment (Red_Hat-21.0.6.0.7-1) (build 21.0.6+7-LTS)
OpenJDK 64-Bit Server VM (Red_Hat-21.0.6.0.7-1) (build 21.0.6+7-LTS, mixed mode, sharing)

Thanks in advance for your help.