$ cat test.pl
use 5.032;
my $foo = 10;
say qq{foo: $foo}
$ perl -d test.pl

Loading DB routines from perl5db.pl version 1.57
Editor support available.

Enter h or 'h h' for help, or 'man perldebug' for more help.

main::(test.pl:2):      my $foo = 10;
  DB<1> x $foo
0  undef
  DB<2> n
main::(test.pl:3):      say qq{foo: $foo}
  DB<2> x $foo
0  10
  DB<3> my $foo = 20

  DB<4> x $foo
0  10
  DB<5> my $foo = 20; say qq{foo: $foo}
foo: 20

  DB<6> x $foo
0  10