Incomplete data bindings in traces for local variables

[istalker2]

Trace for the

rule { i = 1  }

looks like

Enter data.foo.rule = _ {} (qid=0, pqid=0)
Eval data.foo.rule = _ {} (qid=0, pqid=0)
Index data.foo.rule = _ {} (qid=0, pqid=0)
Enter rule = true { i = 1 } {} (qid=1, pqid=0)
Eval i = 1 {} (qid=1, pqid=0)
Exit rule = true { i = 1 } {i: 1} (qid=1, pqid=0)
Exit data.foo.rule = _ {_: true} (qid=0, pqid=0)
Redo data.foo.rule = _ {_: true} (qid=0, pqid=0)
Redo data.foo.rule = _ {_: true} (qid=0, pqid=0)
Redo rule = true { i = 1 } {i: 1} (qid=1, pqid=0)
Redo i = 1 {i: 1} (qid=1, pqid=0)

But for the

rule { i := 1  }

it becomes

Enter data.foo.rule = _ {} (qid=0, pqid=0)
Eval data.foo.rule = _ {} (qid=0, pqid=0)
Index data.foo.rule = _ {} (qid=0, pqid=0)
Enter rule = true { __local3__ = 1 } {} (qid=1, pqid=0)
Eval __local3__ = 1 {} (qid=1, pqid=0)
Exit rule = true { __local3__ = 1 } {__local3__: 1} (qid=1, pqid=0)
Exit data.foo.rule = _ {_: true} (qid=0, pqid=0)
Redo data.foo.rule = _ {_: true} (qid=0, pqid=0)
Redo data.foo.rule = _ {_: true} (qid=0, pqid=0)
Redo rule = true { __local3__ = 1 } {__local3__: 1} (qid=1, pqid=0)
Redo __local3__ = 1 {__local3__: 1} (qid=1, pqid=0)

i.e. instead of i we see __local3__. Although it might reflect how local variables are handled by OPA it doesn't give information to track __local3__ back to i

[tsandall]

We deal with rewritten vars when query results are returned by the rego package. It seems like we need to apply the same kind of logic to the trace events to give callers a result that makes sense to them.