I'm able to confirm Benjamin's notes. The regexp works on 64bit Linux but fails with a 32bit build:

$ CFLAGS="-m32" LDFLAGS="-m32" ./configure
$ make -j10
$ ./python -c "import re; print(re.compile('(.*)\.[0-9]*\.[0-9]*$', re.I|re.S).findall('3.0.0'))"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
RuntimeError: internal error in regular expression engine