if (defined($$l_Name_ref)) {
  print STDERR "1 $$l_Name_ref\n" if (defined($$l_Name_ref));
  print STDERR "2 $l_Name_ref\n";
  if ($$l_Name_ref =~ /^[a-zA-Z]\w+$/) {
    print STDERR "3 $l_Name_ref\n";
    print STDERR "4 $$l_Name_ref\n";
    ...

##</code><code>##

1 MMP_MODULES
2 SCALAR(0x7f80ab361968)
3 SCALAR(0x7f80ab361968)
4 MMP_MODULES
1 TMP_MODULE_HASH
2 SCALAR(0x7f80ad04ed68)
3 SCALAR(0x7f80ad04ed68)

##</code><code>##

Use of uninitialized value in concatenation (.) or string at myfile.pm line 1061.

##</code><code>##

if (defined($$l_Name_ref)) {
  my $l_Name = $$l_Name_ref;
  if ($l_Name =~ /^[a-zA-Z]\w+$/) {
    ...