Maven fails to find local artifact

Question

The local Maven repo tracks where artifacts originally came from using a file named "_maven.repositories" in the artifact directory. After removing it, the build worked. This answer fixed the problem for me.

As the options here didn't work for me, I'm sharing how I solved it:

My project has a parent project (with its own pom.xml) that has many children modules, one of which (A) has a dependency to another child (B). When I tried mvn package in A, it didn't work because B could not be resolved.

Executing mvn install in the parent directory did the job. After that, I could do mvn package inside of A and only then it could find B.

Even in offline mode, maven will check remote repositories if there is a _remote.repositories marker for the dependency. If you need to operate in offline mode, you may need to delete these files.

The simple shell command below deletes these marker files. This is safe to do if you only use offline mode for the machine. I would NOT do this on a machine that needs to pull files down from the web.

I have used this strategy on a build server that is disconnected from the web. We have to transfer the repository to it, delete the marker files and then run in offline mode.

On Linux / Unix you can delete the remote repository marker files this way:

cd ~/.m2
find . -name "_remote.repositories" -type f -delete

Maven remembers when it didn't find something. The key is "resolution will not be reattempted until the update interval of internal has elapsed or updates are forced ->"

The quick solution is to delete your local "repository" subdirectory for the problem artifact - assuming you have fixed the problem with it. :)

mvn -U will force update from remote repository - again, assuming you have now populated remote with said artifact.

When this happened to me, it was because I'd blindly copied my settings.xml from a template and it still had the blank <localRepository/> element. This means that there's no local repository used when resolving dependencies (though your installed artifacts do still get put in the default location). When I'd replaced that with <localRepository>${user.home}\.m2\repository</localRepository> it started working.

For *nix, that would be <localRepository>${user.home}/.m2/repository</localRepository>, I suppose.

If you have <repositories/> defined in your pom.xml apparently your local repository is ignored.