同样的代码和maven命令 mvn -U clean package assembly:assembly -Dmaven.test.skip=true

maven 3.8.8 通过

maven 3.9.6 BUILD FAILURE
[ERROR] Could not find goal 'assembly' in plugin org.apache.maven.plugins:maven-assembly-plugin:3.6.0 among available goals help, single -> [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/MojoNotFoundException