An error that occurs when a search should be retried.
This retry error distinguishes between two different failure modes.
The first is one where potential quadratic behavior has been detected.
In this case, whatever optimization that led to this behavior should be
stopped, and the next best strategy should be used.
The second indicates that the underlying regex engine has failed for some
reason. This usually occurs because either a lazy DFA’s cache has become
ineffective or because a non-ASCII byte has been seen and a Unicode word
boundary was used in one of the patterns. In this failure case, a different
regex engine that won’t fail in these ways (PikeVM, backtracker or the
one-pass DFA) should be used.
This is an internal error only and should never bleed into the public
API.