The iterator of this Seq is already in use/consumed by another Seq
(you might solve this by adding .cache on usages of the Seq, or
by assigning the Seq into an array)

##</code><code>##

use v6;

my @paths = data();
my @dirs.push: $_.split('/') for @paths;    # A
#  @dirs.perl;                              # B
say $_.join('/') for @dirs;                 # C
my $depth = @dirs.map(*.elems).min;         # D

sub data
{
    my $text = q:to/END/;
        /aardvark/bison/camel/dromedary
        /aardvark/bison/camel/dromedary/elephant
        END

    return $text.lines;
}

##</code><code>##

11:03 >perl6 -v
This is Rakudo Star version 2019.03.1 built on MoarVM version 2019.03
implementing Perl 6.d.

12:14 >