To repro, put a debugger in org.springframework.data.repository.core.support.RepositoryFactorySupport#getRepository(java.lang.Class<T>, org.springframework.data.repository.core.support.RepositoryComposition.RepositoryFragments)
Includes parsing the magical method name syntax
Repos are registered as beans on app boot, then their proxies are created lazily when you first autowire the repo.