How do I diagnose why m2e fails to see a repo as a Maven project?

[davidmichaelkarr]

I support a platform with a few hundred services using SpringBoot and Maven, on Eclipse. The vast majority I can import from my git repo and m2e makes all the correct choices, making it a Java and Maven project, and seeing all the required source directories. Sometimes it has trouble seeing all of the generated source directories, but that's easily dealt with.

However, every once in a while I run into a repo that it just can't figure out. I import it, and it sets the javabuilder and maven2builder in the buildSpec of the .project, but that's all it does. It doesn't even create a .classpath file. I've looked carefully at the pom.xml of this repo, and although it has some minor differences from other projects (mostly in the dependencies), I don't see anything unusual that would obviously cause m2e to lose its mind.

Fortunately, all of our services have a similar structure, so I can also work around this by simply copying the .classpath file from another repository, often without changing it at all.

That's what I did with the most recent repo that gave me this problem, and it worked perfectly fine. However, it's annoying that I have to do this.

It would be good if we could figure out what causes this.

I know that you're going to ask for a repeatable test case. That's just not going to happen. I can't even guarantee that a "minimized" version of this project will have the same symptoms.

I wish there were some sort of diagnostic capability in m2e that could give me verbose information about what it is doing, or not doing, so I can tell why it's failing to do anything useful with this repo on import, and hopefully communicate it back to you to make it more resilient.

I'm currently on 2023-12, but I've seen this behavior in numerous older versions.