You are viewing the version of this documentation from Perl blead. This is the main development branch of Perl. (git commit 3f6ffa03359c26fc550d3b5bbd2e1c5d08bc6e21)
${^RE_DEBUG_FLAGS}

The current value of the regex debugging flags. Set to 0 for no debug output even when the re 'debug' module is loaded. See re for details.

This variable was added in Perl v5.10.0.