Add debugging output for when a clay ford build fails.
|= row=build-result:ford
^- (unit [cage cage])
::
+ ?: ?=([%error *] row)
+ ~& [%clay-whole-build-failed message.row]
+ ~
+ ?: ?=([%success [%error *] *] row)
+ ~& [%clay-first-failure message.head.row]
+ ~
+ ?: ?=([%success [%success *] [%error *]] row)
+ ~& [%clay-second-failure message.tail.row]
+ ~
?. ?=([%success [%success *] [%success *]] row)
~
`[(result-to-cage:ford head.row) (result-to-cage:ford tail.row)]
