The old standby local $_; will fail with

Can't localize lexical variable $_ at junk line 13.  (#1)
    (F) You used local on a variable name that was previously declared
+ as a
    lexical variable using "my" or "state".  This is not allowed.  If 
+you want to
    localize a package variable of the same name, qualify it with the
    package name.
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I think local $_ should just work, for those who can't remember to use our $_;

At a minimum, I think the perldiag entry for this error should say to use our $_;