Crash with Proxy as argument to native parameters

[CurtTilmes]

The Problem

test.pl: multi MAIN('foo') {}; sub USAGE { print $*USAGE }

Expected Behavior

Usage:
  test.pl foo

Actual Behavior

Cannot auto-decontainerize argument
in sub USAGE at <tmp> line 1
 in block <unit> at <tmp> line 1

[zoffixznet]

Golfed to:

m: my $x := Proxy.new: :FETCH{"42\n"}, :STORE(-> $, $ {}); print $x
rakudo-moar 08b449e1a: OUTPUT: «Cannot auto-decontainerize argument␤ in block <unit> at <tmp> line 1␤␤»

Bisected to: 0d053ab

Fairly sure a strategic decont in IO::Handle.print will avoid the issue, but should it be fixed in a more robust way? Like whatever does the auto-decont to learn how to decont Proxy stuff?

[zoffixznet]

I think this golfier golf answers my question:

m: -> str { }( Proxy.new: :FETCH{"42\n"}, :STORE(-> $, $ {}) )
rakudo-moar 08b449e1a: OUTPUT: «Cannot auto-decontainerize argument␤  in block <unit> at <tmp> line 1␤␤»

m: -> int { }( Proxy.new: :FETCH{42}, :STORE(-> | {}) )
rakudo-moar 08b449e1a: OUTPUT: «Cannot auto-decontainerize argument␤  in block <unit> at <tmp> line 1␤␤»