How do you troubleshoot lazy loading failures caused by missing weaving in EclipseLink?

A common symptom is a lazy relationship that either loads eagerly regardless of the fetch = FetchType.LAZY annotation, or throws an error when accessed outside an active persistence context, both of which usually trace back to weaving not actually being applied to the deployed entity classes.

1. Confirm weaving is enabled - check that eclipselink.weaving isn't set to false in persistence.xml; it defaults to enabled, but is sometimes disabled during debugging and left that way.
2. Check for a Java agent (dynamic weaving) - confirm the -javaagent flag pointing at EclipseLink's weaving agent is actually present on the JVM's startup command, or that the application server's own weaving support is active.
3. Check the build for static weaving - if relying on static weaving, confirm the Ant task or Maven/Gradle plugin actually ran and its output classes (not the unwoven originals) are what's deployed.
4. Inspect the deployed class file - a woven class contains extra synthetic fields and methods (like _persistence_... prefixed members); their absence confirms weaving didn't run against that build artifact.
5. Check for classes loaded before weaving could apply - dynamic weaving only affects classes loaded after the agent registers; entities loaded very early in startup, before the persistence unit initializes, can end up unwoven.

Once weaving is confirmed active, lazy fields behave transparently again; the fallback indirection EclipseLink otherwise uses is functional but noticeably less efficient, which is often the first clue something is wrong even before an outright error appears.