From @usev6

There are two skipped tests in S32-list/map.t which can be shortened to something like​:

$ perl6 -e 'say (1,2,3).map({$^a + $^b})'
Too few positionals passed; expected 2 arguments but got 1
  in block <unit> at -e​:1

The tests seem to expect that placeholder arguments which get no value are treated as zeros.

Raku/roast@92fca54519ece3351265e93 changed the test to make sure that the signature of the block must always match the arguments given. The auto-generating $^a syntax will never create optional parameters. So the original tests were never going to pass. The new test now codify the current behaviour.