I don't know
I think you might be thinking of regex recursive pattern recursion limit
Research
A place to look ( perldeltas )
pod\
perl5100delta:backtracking into a recursed pattern, whereas in PCRE the recursion is
pod\
perl5101delta:=item C<Deep recursion on subroutine "%s">
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perl5101delta:Tests for the interaction of regex recursion and threads.
pod\
perl5120delta:F<t/op/reg_email_thr.t> tests the interaction of regex recursion and threads.
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perl5120delta:C<Deep recursion on subroutine "%s">
pod\
perl5160delta:Missing aliases added, a deep recursion error fixed and various
pod\
perl5180delta:Lexical variables are now sane as regards scope, recursion and closure
pod\
perl5180delta:lexical variables. Formerly under recursion all calls would share the same
pod\
perl5181delta:Deep recursion warnings no longer crash lexical subroutines. [RT #118521]
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perl5200delta:Deep recursion warnings no longer crash lexical subroutines. [RT #118521]
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perl5200delta:recursion, the filehandle was losing the "$fh" part of the name. This has been
pod\
perl5202delta:recursion when dumping deep data structures.
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perl5220delta:Do not check recursion on optional dependencies.
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perl5220delta:recursion when dumping deep data structures.
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perl5220delta:a separate state for each recursion level (the number of times the
pod\
perl5230delta:prevents infinite recursion when the now fatal error also causes
pod\
perl581delta:recursion, though.
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perl586delta:C<goto &> is now more robust - bugs in deep recursion and chained C<goto &>
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perl589delta:Perl no longer segfaults (due to infinite internal recursion) if the locale's
Another place http://perl5.git.perl.org/perl.git?a=search&h=HEAD&st=grep&s=recursion -> http://perl5.git.perl.org/perl.git/blob?f=t/op/recurse.t ( # check ok for recursion depth > 65536)
And another http://perl5.git.perl.org/perl.git?a=search&h=HEAD&st=free&s=recursion
And another site:http://www.nntp.perl.org/group/perl.perl5.porters/ maximum recursion
And another https://rt.perl.org/Public/Search/Simple.html?q=+recursion
site:metacpan.org maximum recursion , site:search.cpan.org maximum recursion
maximum recursion -> Recursion is of unlimited depth.
So in summary, there is a regex recursive pattern limit, configurable