From dougljenkins@gmail.com

I would expect this code to ignore the conversion of $foo if no value is
passed for it.

$ perl6 -e 'sub (Int(Cool) :$foo){}()'

Use of uninitialized value of type Cool in numeric context
  in sub at -e line 1

IRC discussion​: https://irclog.perlgeek.de/perl6/2017-01-01#i_13832608

From @zoffixznet

On Sun, 01 Jan 2017 09​:06​:32 -0800, dougljenkins@​gmail.com wrote​:

I would expect this code to ignore the conversion of $foo if no value is
passed for it.

$ perl6 -e 'sub (Int(Cool) :$foo){}()'

Use of uninitialized value of type Cool in numeric context
in sub at -e line 1

IRC discussion​: https://irclog.perlgeek.de/perl6/2017-01-01#i_13832608

Thank you for the report. This is now fixed in branch `post-release`.

Fix​: rakudo/rakudo@ae697080d2d5225
Test​: Raku/roast@6457b4fab81809c5a

The RT System itself - Status changed from 'new' to 'open'

@zoffixznet - Status changed from 'open' to 'resolved'

From @zoffixznet

On Wed, 17 Jan 2018 15​:48​:31 -0800, cpan@​zoffix.com wrote​:

On Sun, 01 Jan 2017 09​:06​:32 -0800, dougljenkins@​gmail.com wrote​:

I would expect this code to ignore the conversion of $foo if no value is
passed for it.

$ perl6 -e 'sub (Int(Cool) :$foo){}()'

Use of uninitialized value of type Cool in numeric context
in sub at -e line 1

IRC discussion​: https://irclog.perlgeek.de/perl6/2017-01-01#i_13832608

Thank you for the report. This is now fixed in branch `post-release`.

Fix​: rakudo/rakudo@ae697080d2d5225
Test​: Raku/roast@6457b4fab81809c5a

This has been reverted for now, in light of rakudo/rakudo#1517
(and somewhat rakudo/rakudo#1519 too)

We need to figure out how/whether handle the cases whether the two types of
the coercer aren't subclasses and I rather we don't push the original fix into
a release before we do that.

Keeping this Issue as resolved, with the problem being continued on rakudo/rakudo#1517