How do you troubleshoot slow or failing GraalVM native image builds in Micronaut?

Start by reading the native-image build log carefully rather than guessing; most failures fall into a handful of recurring categories: missing reflection/resource configuration for a third-party library, unsupported dynamic class loading, or a dependency that simply isn't native-image-ready.

1. Check reachability metadata first. If a third-party library isn't a Micronaut module, it may lack the GraalVM reachability metadata Micronaut relies on; check the GraalVM reachability metadata repository or the library's own docs before writing custom config by hand.
2. Isolate the failing dependency by temporarily removing suspect libraries and rebuilding, narrowing down which one triggers the failure.
3. Add targeted reflect-config.json/resource-config.json entries only for the specific classes that need runtime reflection, rather than broad blanket configuration that bloats the binary and hides real problems.
4. Watch build memory and time separately. A build that's merely slow often just needs more heap allocated to the native-image process, while a build that fails outright is a configuration or compatibility problem, not a resource one.
5. Test incrementally by building a minimal reproduction of the failure rather than iterating on the full application, since native-image build cycles are expensive.

Once past initial setup, most ongoing pain comes from adding a new dependency that wasn't vetted for native compatibility, so it's worth checking new libraries against this before assuming there's a Micronaut-specific bug.