Copied from one of the Perl Discords:

By user "timka7060":

Who can figure this out. I narrowed down my issue in some other code to this simple use case: 
# Can print $v only once!!!
# Second call returns undef.
# Some coderef optimization???
# Lexical variable goes undef on second call.
#
sub {
    my $v = 111;
    eval q(
        eval 'print $v, "\n"'; # 111
        eval 'print $v, "\n"'; # undef
    );
}->();

[download]

User "tyrrminal" replies with:

If you enable warnings, you see a line Variable "$v" is not available at (eval 3) line 1. Googling that led me to a stack overflow response which seems to relate to your case (2nd answer, starting with See perldiag)

timka7060's reaction:

So why does the first eval output 111?
(I'd figure either both lines should be 111 or both undef.)
Btw, prior to 5.10, both lines would output 111: https://perlbanjo.com/b28dce8db2
This is a simple fix, but only for a single variable: https://perlbanjo.com/13dbb8d48d

My observation: 

sub {
    my $v = 111;
    eval q(
        eval 'print $v, "A\n"';
        eval 'print $v, "B\n"';
        print $v, "C\n";
    );
}->();

[download]
Now, none of either A or B sees $v, but C (obviously) does.

What's going on here?

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

In reply to Lexical variable not available by choroba

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