In one of my Maven projects, dependency resolution will succeed once, then fail for later build attempts:
[WARNING] The POM for commons-logging:commons-logging:jar:1.1.1 is missing, no dependency information available
[WARNING] The POM for commons-httpclient:commons-httpclient:jar:3.1 is missing, no dependency information available
[WARNING] The POM for javax.mail:mail:jar:1.4.4 is missing, no dependency information available
…and so on, until I delete the maven-metadata-local.xml files corresponding to the failing artifacts (e.g. ~/.m2/repository/commons-logging/commons-logging/maven-metadata-local.xml). After those files are deleted, the next mvn invocation proceeds properly; the metadata files are restored by that invocation (presumably as part of the process of checking my upstream repositories/mirrors for updated artifacts), and I am again presented with the above errors until I again delete the metadata files.
This impacts multiple projects, though it appears to be limited to a particular set of dependencies. I suppose I could go nuclear and blow away my local repo, but I’d like to understand what the problem is.
Thoughts?
Update: It looks like it’s the maven-invoker-plugin (which these builds are using for general-purpose integration testing) that is producing these maven-metadata-local.xml files. I’m not using an integration-testing-only local repo as described here, simply because doing so causes the re-downloading of all transitive dependencies (unless you want to maintain an integration-specific settings.xml file!!!). I’ve used the invoker plugin with a variety of other projects in this way with good results — certainly never encountering a wedged local repository in the process like this.
Update 2 OK, this is repeatable, even after starting with a completely fresh local repository. This is on OS X, Java 1.6.0_24 with Maven 3.0.3; note that Maven 2.2.1 does NOT exhibit this problem.
Here’s one of the projects in question: the 1.3.0-compat branch of rummage. To reproduce:
> mvn clean test
# no error -- can run this and other builds that don't involve maven-invoker-plugin all day w/o problems
> mvn clean integration-test
# FAIL: "Could not resolve dependencies", with warnings as noted above
> mvn clean test
# FAIL: "Could not resolve dependencies", with warnings as noted above
Once the local repository is borked (by the generation of the maven-metadata-local.xml files, AFAICT), no builds will get past the dependency resolution stage.
Running mvn -X reveals lines like this for each artifact that is later apparently not found:
[DEBUG] Verifying availability of /Users/chas/.m2/repository/javax/mail/mail/1.4.4/mail-1.4.4.jar from []
Of course, /Users/chas/.m2/repository/javax/mail/mail/1.4.4/mail-1.4.4.jar et al. does exist, as does /Users/chas/.m2/repository/javax/mail/mail/1.4.4/mail-1.4.4.pom. Totally puzzled. At this point, I’m assuming this is a bug in Maven 3 (or some underlying library), now that I see that 2.2.1 is clean.
Update 3 Bug report filed with Maven project.
This issue is resolved in aether 1.12, one rev above the aether 1.11 library that ships with Maven 3.0.3. Replacing aether 1.11 with 1.12 in one’s Maven install results in expected behaviour (as noted in the bug I filed). Here’s hoping Maven 3.0.4 is released with aether 1.12 ASAP. 🙂