The fix for JMC-6000 [0] introduced  an exclusion on META-INF/MANIFEST.MF [1], in which the manifest is now absent from the produced agent jar. Trying to run the agent results in an error: "Error opening zip file or JAR manifest missing : target/org.openjdk.jmc.agent-1.0.0-SNAPSHOT.jar"

This doesn't affect the build when running "mvn package", just that the resulting jar won't be usable.

However, when running "mvn verify" there are some tests that use the agent which will cause the build to fail.

It might be nice to have the agent built automatically on PRs similar to jmc-core and jmc.

[0] https://bugs.openjdk.java.net/browse/JMC-6000
[1] https://github.com/openjdk/jmc/commit/db64b84a#diff-e5b35c4385af58d8c068cdc579717b76R73