From zefram@fysh.org

set($((2,).Seq)).perl
set((2,).Seq)
set($((2,).Seq)).perl.EVAL.perl
set(2)

Failure of .perl.EVAL round-tripping. Set.perl's output isn't taking
account of the flattening imposed by the set constructor.

-zefram

From zefram@fysh.org

Set.new((2,).Seq,3).perl
set((2,).Seq,3)
Set.new((2,).Seq,3).perl.EVAL.perl
set(3,2)

Failure of .perl.EVAL to round-trip. Don't know which side of the trip
is at fault.

-zefram

From zefram@fysh.org

Oops, this is mostly a duplicate of [perl #​129015]. Sorry.

-zefram