One ivy-build job can build multiple ivy modules that are located in one git repository:

repository/
├── Module A/
│   ├── src/...
│   ├── build.xml
│   └── ivy.xml
├── Module B/
│   ├── src/...
│   ├── build.xml
│   └── ivy.xml
├── Module C/
│   ├── src/...
│   ├── build.xml
│   └── ivy.xml
└── ...

If one of the modules is removed from resp. renamed in the repository, the ivy plugin continues to trigger builds. These builds fail with "FATAL: Unable to find build script at...", as the module does not exist any more (at this location).

Current workaround: delete the module directory under $JENKINS_HOME$/jobs/<jobname>/modules/<module directory> and restarting jenkins resp. "Reload Configuration from Disk"