committable6

query

use v6;␤␤my $supply = supply {␤    die;␤}␤␤react {␤    whenever $supply {␤␤    }␤}␤

result

¦«2015.12,2016.01.1,2016.02,2016.03,2016.04,2016.05,2016.06»:
Died
  in block <unit> at /tmp/U1QdAYYndp line 7

 «exit code = 1»
¦«2016.07.1»:
No such method 'CALL-ME' for invocant of type 'Bool'
  in block <unit> at /tmp/U1QdAYYndp line 7

 «exit code = 1»
¦«2016.08.1»:
Access denied to keep/break this Promise; already vowed
  in any  at /tmp/whateverable/rakudo-moar/a07a2e173cfc24f1bec549d2d5b79ef978e46b58/share/perl6/runtime/CORE.setting.moarvm line 1
  in block <unit> at /tmp/U1QdAYYndp line 7

 «exit code = 1»
¦«2016.09»:
Access denied to keep/break this Promise; already vowed
  in any  at /tmp/whateverable/rakudo-moar/4b32fcab2192054b82312cde4c235adda0b8ac4d/share/perl6/runtime/CORE.setting.moarvm line 1
  in block <unit> at /tmp/U1QdAYYndp line 7

 «exit code = 1»
¦«2016.10»:
Access denied to keep/break this Promise; already vowed
  in any  at /tmp/whateverable/rakudo-moar/eb3123e5e60fa1635ed1ee121cec1290c290044a/share/perl6/runtime/CORE.setting.moarvm line 1
  in block <unit> at /tmp/U1QdAYYndp line 7

 «exit code = 1»
¦«2016.11,2016.12,2017.01,2017.02,2017.03,2017.04.3,2017.05,2017.06,
  2017.07,2017.08,2017.09»:
Tried to get the result of a broken Promise
  in block <unit> at /tmp/U1QdAYYndp line 7

Original exception:
    Died
      in block <unit> at /tmp/U1QdAYYndp line 4

 «exit code = 1»
¦«2017.10,2017.11,HEAD(e5b660e)»:
An operation first awaited:
  in block <unit> at /tmp/U1QdAYYndp line 7

Died with the exception:
    Died
      in block <unit> at /tmp/U1QdAYYndp line 4

 «exit code = 1»