http://www.perlmonks.org?node_id=11108927


in reply to Re^3: Note on usage of ours variables and a question
in thread Note on usage of ours variables and a question

Looks like one needs additional underscore:
${^_MYDEBUG} = 1;

"No name that begins with ^_ will acquire a special meaning in any future version of Perl; such names may therefore be used safely in programs. $^_ itself, however, is reserved."

"In particular, the special ${^_XYZ} variables are always taken to be in package main , regardless of any package declarations presently in scope."