>perl -MO=Concise -e"my $data = 1; print $data;"
a  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 1 -e:1) v ->3
5     <2> sassign vKS/2 ->6
3        <$> const[IV 1] s ->4
4        <0> padsv[$data:1,2] sRM*/LVINTRO ->5
6     <;> nextstate(main 2 -e:1) v ->7
9     <@> print vK ->a
7        <0> pushmark s ->8
8        <0> padsv[$data:1,2] l ->9       <-- It uses the lexical,
-e syntax OK                                  not a constant.

>perl -MO=Concise -e"print 1;"
6  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 1 -e:1) v ->3
5     <@> print vK ->6
3        <0> pushmark s ->4
4        <$> const[IV 1] s ->5            <-- This is a constant.
-e syntax OK