>perl -wMstrict -le
"my @mystrings = ('string') x 10_000;
 ;;
 my %evaled;
 for my $i (0 .. $#mystrings) {
   eval qq{ qr{\$mystrings[$i]} };
   $evaled{$i} = $@;
   }
 ;;
 my $ok =()= grep !$_, values %evaled;
 printf qq{ok  == %4d \n}, $ok;
 my $bad =()=
   grep $_ &&
        /Global symbol \"\$mystrings\" requires explicit package name/,
   values %evaled
   ;
 printf qq{bad == %4d \n}, $bad;
"
ok  ==  392
bad == 9608