My .war project was building and deploying ok, but Eclipse said there was a problem — the project had a red X by it in the Package Explorer, and in the Problems window it said
Project ‘xa-example’ is missing required library: ‘…\org\apache\activemq\activeio-core\3.1-SNAPSHOT\activeio-core-3.1-SNAPSHOT-tests.jar’
I couldn’t understand why I was getting this, because I had already excluded the activeio-core library:
What I needed to do was run the maven eclipse:clean and eclipse:eclipse goals. This rebuilt the .classpath file, which is where there was the stray reference to the activeio-core-3.1-SNAPSHOT-tests.jar file.
I had thought I was running the clean goal already, but the External Tools configuration I was using actually ran the maven clean and install goals, not eclipse:clean and eclipse:eclipse.
Once I ran the eclipse:clean and eclipse:eclipse goals, the error went away.