It may happen that you’re trying to fix some issues that affects the release of a maven project and therefore you apply some changes locally and then run
mvn release:prepare -DdryRun=true -Darguments=-DskipTests
Then you get an error message like
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-release-plugin:2.5.3:prepare (default-cli) on project jackrabbit-oak: Cannot prepare the release because you have local modifications : [ERROR] [oak-api/src/main/java/org/apache/jackrabbit/oak/api/PropertyState.java:modified] [ERROR] [oak-api/src/main/java/org/apache/jackrabbit/oak/api/jmx/CacheStatsMBean.java:modified] [ERROR] [oak-api/src/main/java/org/apache/jackrabbit/oak/api/jmx/CheckpointMBean.java:modified] [ERROR] [oak-api/src/main/java/org/apache/jackrabbit/oak/api/jmx/IndexStatsMBean.java:modified] [ERROR] [oak-api/src/main/java/org/apache/jackrabbit/oak/api/jmx/RepositoryStatsMBean.java:modified]
Sure. release-plugin is giving you an extra check about any local changes that may not end in the release. However you don’t want to commit those changes to the SCM just yet; you want first to see if they works.
A “quick” workaround is on the command line in the (verbose) form of
mvn release:prepare -DdryRun=true -Darguments=-DskipTests -DcheckModificationExcludeList=oak-api/src/main/java/org/apache/jackrabbit/oak/api/*,oak-api/src/main/java/org/apache/jackrabbit/oak/api/jmx/*
You can as well specify something in the poms directly however I never had the need.