gistfile1.txt

Code:
say Set ⊇ Set ?? 'present' !! 'not present';

¦«2015.12»:
Cannot look up attributes in a type object
  in block <unit> at /home/bisectable/git/whateverable/data/regressionable/15267445/snippet line 1
 «exit code = 1»

¦«2016.06»:
Cannot look up attributes in a type object
  in block <unit> at /home/bisectable/git/whateverable/data/regressionable/15267445/snippet line 1
 «exit code = 1»

¦«2016.12»:
Invocant requires an instance of type Setty, but a type object was passed.  Did you forget a .new?
  in block <unit> at /home/bisectable/git/whateverable/data/regressionable/15267445/snippet line 1
 «exit code = 1»

¦«2017.06»:
present

¦«f72be0f130cf»:
present


Possible IRC discussion: https://irclog.perlgeek.de/perl6/2017-10-06#i_15267445
Bisectable: (2017-05-22) https://github.com/rakudo/rakudo/commit/ad8fa55297ecdab6b514bcf5aaa93e7cbaa91754