/(?{"{"})/ # Check it outside of eval too
EXPECT
Sequence (?{...}) not terminated or not {}-balanced at - line 1, within pattern
-/(?{"{"})/: Sequence (?{...}) not terminated or not {}-balanced at - line 1.
+Sequence (?{...}) not terminated or not {}-balanced at <HERE< mark in regex m/(?{ <<<HERE<<< "{"})/ at - line 1.
########
/(?{"{"}})/ # Check it outside of eval too
EXPECT