clay: insert %nest-fail into trace conditionally
Previously, we would stack on the ~| for every file we had previously
processed, even though we only want it in the trace for actual failures.
[%kttr %make [%wing ~[%map]] ~[[%base %atom %ta] spec.i.raz]]
|-
?~ res ~
+ ?. (~(nest ut type) | p.q.n.res)
~| [%nest-fail path.i.raz p.n.res]
- ?> (~(nest ut type) | p.q.n.res)
+ !!
:- [p.n.res q.q.n.res]
[$(res l.res) $(res r.res)]
::
