According to the perldebguts:
Each array @{"_<$filename"} holds the lines of $filename for a file compiled by Perl. The same is also true for evaled strings that contain subroutines, or which are currently being executed. The $filename for evaled strings looks like (eval 34).
Values in this array are magical in numeric context: they compare equal to zero only if the line is not breakable.
But perl 5.36 warns in my debugger as: Argument "use v5.36;\n" isn't numeric in numeric eq (==) at
There is a simple comparison: if $lines[$lineno] == 0
Do I do something wrong?

In reply to Perl 5.36 warns for magic comparison by hurricup

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