use 5.012;
    use Sub::Name 'subname';
    use B;
    
    sub get_sub_name { B::svref_2object(shift)->GV->NAME }
    
    my $ref = sub { say 'Our name is:    ' . (caller(0))[3] };
    
    $ref->();
    say 'Before subname: ' . get_sub_name($ref);
    
    subname 'the_pad_test', $ref;
    
    $ref->();
    say 'After subname:  ' . get_sub_name($ref);
    
    print "the_pad_test(): ";
    eval { the_pad_test() };
    print $@ =~ /^Undefined sub/ ? "fails (correct)\n" : "ERROR: $@";


##</code><code>##

Our name is:    main::__ANON__
Before subname: __ANON__
Our name is:    main::the_pad_test
After subname:  the_pad_test
the_pad_test(): fails (correct)