- Fire up NX3 with a debugger
- Set a breakpoint in RepositoryManagerImpl.track() (https://github.com/sonatype/nexus-internal/blob/8f1102843b5c02ad05a23e1d18e9ff2e24f27ee3/components/nexus-repository/src/main/java/org/sonatype/nexus/repository/manager/RepositoryManagerImpl.java#L158)
- Create a new repo, observe the breakpoint gets hit and leave the thread suspended at it
- Create another repo, observe the breakpoint gets hit again, i.e. two concurrent threads can execute that method which modifies repositories, a simple HashMap...