Reports row-set differences and a count per verdict, then lists every
variable that is not "identical". No overall pass/fail is printed, by
design: see compare_built().
Details
Identifiers are not printed by default. In this group's datasets
ccfidu is a medical record number concatenated with a date of surgery,
which is PHI; printing it would place PHI in terminals, logs, and captured
test failures. The identifiers remain available in the rows attribute for
a caller who needs them to chase a discrepancy.