join from "{from}" to "{to}" would close a j...

Warnings reference › router:join-cycle

Identifier

router:join-cycle

Raised by

Data Router

Since

1.84.0

What happened

A join graph is a DAG: a source joins or collects from another, which may in turn join from a third. A declaration that would point the graph back at itself - a source collecting from a source that transitively collects from it - has no stable evaluation order, so the closing join is refused and that source's rows pass through unjoined rather than the router recursing forever.

The fix

Break the cycle: point the join at a source that does not (transitively) depend on this one.

Reference

Covered in full at the API reference.