问题
I'm trying to purge the local repository of a project dependency before launching releasing it in order to make sure every dependency required is on the central repository and is downloaded from it.
In the project folder (containing the pom.xml), I launch the following command:
mvn clean dependency:purge-local-repository -DreResolve=false -Dverbose=true
The project's POM is very simple and just have a declared dependency to junit:junit:3.8.1
The command's output give me:
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building corelib-api 0.1.2-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.4.1:clean (default-clean) @ corelib-api ---
[INFO] Deleting d:\Users\fpaillard\git-repositories\TEST_CORELIB\corelib-api\target
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building corelib-api 0.1.2-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-dependency-plugin:2.1:purge-local-repository (default-cli) @ corelib-api ---
[WARNING] Missing POM for junit:junit:jar:3.8.1
[INFO] Skipping: corelib-api. It cannot be resolved.
[INFO] Nothing to do for project: test:corelib-api:jar:0.1.2-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.953s
[INFO] Finished at: Mon May 14 11:34:40 CEST 2012
[INFO] Final Memory: 6M/15M
[INFO] ------------------------------------------------------------------------
When I look in the local repository (path checked with mvn help:effetive-settings), junit JARs nor POMs are still in .m2/repository/junit/junit/3.8.1 folder.
Isn't dependency:purge-local-repository supposed to delete it?
I don't understand the WARNING of the output above. Why is junit:junit:jar:3.8.1 POM missing? It is still present at .m2/repository/junit/junit/3.8.1/junit-3.8.1.pom
Is the problem related to the INFO line Skipping: corelib-api. It cannot be resolved.? corelib-api is the artifact name of the project I ran mvn dependency:purge-local-repository against.
回答1:
I know this is old, but I had the same issue, and adding -DactTransitively=false to the command line fixed this issue. I'm unable to tell why it helped, but it did...
I hope this helps.
回答2:
Looking at the documentation, disabling the actTransitively option causes the purge goal to only purge the dependencies that are named directly by your pom.xml. When it is time for the build, Maven automatically pulls not only your direct dependencies, but all of the TRANSITIVE dependencies down into your local repo as well.
When the purge goal is looking for what to delete, if it finds other dependencies in the dependencies' poms, it transverses those dependencies to figure out the entire tree in your local repository that can be purged. To do this, it at least needs the transitive project's pom.xml. If it cannot find it in the local repo, or if it thinks there might be a more recent version to analyze, it will go to the external repositories to find it.
I don't think it actually tries to download full project content before it starts purging. But since it at least pulls down the projects' pom.xml files, it will complain if it can't find one just like it would if it were resolving dependencies for an actual build.
Besides just preventing Maven from accessing external repositories while purging, another practical reason would be if you have two projects that have the same transitive dependency, and you don't want the purge from one to affect the performance of the other (since the latter will have to download any missing dependencies again).
On the other hand, something to carefully consider is that if you do NOT allow the purge to consider all of the transitive dependencies possible, you stand to leave a set of downstream dependencies sitting in your local repository that you would otherwise have wanted to remove.
I could make a case for saying that the output you are getting is either unnecessary or preventable with another flag like "reportInaccessibleDependencies=false". But unless it is killing your build, I wouldn't say it is anything to worry about.
来源：https://stackoverflow.com/questions/10581132/what-is-maven-dependencypurge-local-repository-supposed-to-do