Maven not downloading latest snapshots or releases

Ever had issues with maven not downloading the latest snapshots when you know for a fact new snapshots are available? Or your CI environment just deployed a new release (2.0), but when another Hudson job builds, maven does not download the latest 2.0 release artifact. Want an automated solution so you dont have to manually delete the artifacts from your local repository just so maven will download the latest?

Force maven to download latest snapshots
Our company uses Hudson for our automated CI environments. Our project basically has two jobs. The first job checks out and builds HEAD when modified and deploys SNAPSHOT WARs to our companies maven2 repository (artifactory). The second job, which builds nightly, uses maven to download the SNAPSHOT WARs from artifactory, creates an EAR, deploys it to JBoss, and runs integration tests. By default, maven will check once a day for changes to snapshots, so when our second job was triggered, maven inside hudson was not downloading the latest SNAPSHOT WARs.

The solution was to append the -U in the maven goals (run mvn -help). It stands for update-snapshots and tells maven to update all snapshots no matter what.


Force maven to download latest releases
Our next problem was when we created a branch and started creating release artifacts such as 2.0. Unfortunately the description given by maven for the -U option is incorrect (or at least in v 2.0.9), "Forces a check for updated releases and snapshots on remote repositories". As much as I tried, the -U option wouldnt work in our hudson job to force maven to download the latest non-snapshot releases.

The only current solution I know of is to use the maven-dependency-plugin and its goal purge-local-repository. So in your maven goals at some point execute mvn dependency:purge-local-repository and maven will physically delete your projects artifacts from the local repository (/home/user/.m2/repistory) and its transitive dependencies (I think). I tried setting the actTransitively to false and it didnt work for us so I just removed it. I also set verbose to true so I could see what maven deleted in Hudsons console output.



The pipes are used to separate out different goals to isolate its classpath or properties. That way we can skip tests in one run, and then run them in the next all in the same goals section.

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