$ ./perl -MO=Concise -e 'my *x'
Can't declare ref-to-glob cast in "my" at -e line 1, at EOF
-e had compilation errors.
5  <@> leave[1 ref] KP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 1 -e:1) ->3
4     <1> rv2gv sKR/1 ->5
3        <#> gv[*x] s ->4