3.0 regression from 2.4.7 - regex generated for QuotedString

[ptmcg]

>>> from pyparsing import QuotedString
>>> QuotedString('*/',endQuoteChar='/*')                                                                                                  
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/ptmcg/.virtualenvs/py37/lib/python3.7/site-packages/pyparsing/core.py", line 3163, in __init__
    "invalid pattern {!r} passed to Regex".format(self.pattern)
ValueError: invalid pattern '\\*/(?:(?:(?:/(?!*)))|(?:[^/\\n\\r]))*/\\*' passed to Regex

>>> from pyparsing_247 import QuotedString
>>> QuotedString('*/',endQuoteChar='/*')                                                                                                  
quoted string, starting with */ ending with /*