A successful test run 

$ prove -l t/10-vp-basics.t
t/10-vp-basics.t .. 1/? Test Suite input length mismatch: requested: 4096
        got: 7, data:
Test Suite input length mismatch: requested: 4096
        got: 0, data:
Test Suite input length mismatch: requested: 4096
        got: 0, data:
Test Suite input length mismatch: requested: 4096
        got: 0, data:
Test Suite input length mismatch: requested: 4096
        got: 0, data:
Test Suite input length mismatch: requested: 4096
        got: 0, data:
t/10-vp-basics.t .. ok
All tests successful.
Files=1, Tests=5,  1 wallclock secs ( 0.03 usr  0.00 sys +  0.20 cusr  0.02 csys =  0.25 CPU)
Result: PASS