From @zoffixznet

The circularity detection[^1] code, seems to incorrectly detect this case as circularity​:

16​:28 eveo m​: multi infix​:<+>(Real, Pair $ where {.value === True}) { 42 }; say 1 + :a;
16​:28 camelia rakudo-moar 14d757​: OUTPUT​: «===SORRY!===␤Circularity detected in multi sub types for &infix​:<+>␤»
16​:28 eveo m​: multi infix​:<+>(Real $ where {True}, Pair $ where {.value === True}) { 42 }; say 1 + :a;
16​:28 camelia rakudo-moar 14d757​: OUTPUT​: «===SORRY!===␤Circularity detected in multi sub types for &infix​:<+>␤»

16​:28 eveo m​: multi infix​:<+>(Int, Pair $ where {.value === True}) { 42 }; say 1 + :a;
16​:28 camelia rakudo-moar 14d757​: OUTPUT​: «42␤»

[1] https://github.com/rakudo/rakudo/blob/14d757131159b536d64447f567bc9a8324a271ca/src/Perl6/Metamodel/BOOTSTRAP.nqp#L2157

From @zoffixznet

Some extra comments on this issue​: https://irclog.perlgeek.de/perl6/2017-09-15#i_15169171

15​:15 jnthn Did anyone actually take all the candidates and manually draw out the DAG? :)
15​:17 I can't imagine the cycle detection is a false positive.
15​:17 It is interesting that it ends up with a cycle though