Bizarre copy of ARRAY in sassign at C:/progfile/Perl-5.8.8/lib/Carp/Heavy.pm line 45.

This also manifests itself as: "panic: attempt to copy freed scalar"

Patch for Carp in case anyone is interested. Find the call to format_arg in Carp.pm or Carp/Heavy.pm (depending on version), and replace with (prefix @args with my depending on version also. E.g. in 5.8.8 it's "my @args" in Heavy.pm, in 5.14.1 it's just "@args" in Carp.pm):

    @args = map {
        local $@;
        my $tmp = eval { Carp::format_arg($_) };
        defined($tmp) ? $tmp : 'unknown';
    } @DB::args;
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And now instead of an unhelpful error message referring to a line in Carp, you'll get the stack trace you wanted, albeit with one or more 'unknown' arguments shown in the function calls.