When playing aroud with job dependencies, configured as free style projects and simple windws batch commands, I discovered that cyclic job dependencies are not detected.
Neither when saving configuration nor when running the, supposed, "parent" job.
E.g.
JobA is configured to trigger another projet (Build Other Project) JobB wich is on its turn configured to trigger JobC.
And unfortunately, JobA is finally configured to be lauched after JobC is finished ("Build after other projects are built").

It results in a cyclic execution with absolutely no warning.
I think that the cyclic dependency should be at least detected at configuration time and should probably forbid the execution of such a set of jobs.