Not all core functions can be overridden. print is one of those that cannot.

Even the following doesn't work

package MyPrint;

sub print {
   shift;
   CORE::print("[\n");
   CORE::print(@_);
   CORE::print("]\n");
}

package main;

bless *STDOUT{IO}, 'MyPrint';
print("Hello World!\n");            # builtin
print STDOUT ("Hello World!\n");    # builtin
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but this does

STDOUT->print("Hello World!\n");    # custom
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I think tieing also works.