With older perls (5.16 - 5.20) the test suite fails like this:
Can't enable unknown feature re_strict at t/add-schema.t line 6.
BEGIN failed--compilation aborted at t/add-schema.t line 6.
t/add-schema.t ..........................
Dubious, test returned 255 (wstat 65280, 0xff00)
No subtests run
With older perls (5.16 - 5.20) the test suite fails like this: