+The implementation was tweaked to work around several limitations of vanilla C<perl> pragmas : it's thread safe, and doesn't suffer from a C<perl 5.8.x-5.10.0> bug that causes all pragmas to propagate into C<require>d scopes.
+
+With 5.8 perls, the pragma does not propagate into C<eval STRING>.
+This is due to a shortcoming in the way perl handles the hints hash, which is addressed in perl 5.10.
+