help need: error while serialize following pattern (?P<major>\d+)\.(?P<minor>\d+)\.(?P<patch>\d+)\.(?P<build>\d+)

I need to support following version patter like : 0.0.0.0 i have following config file

[bumpversion]
current_version = 0.0.0.0
commit = True
tag = False
parse = (?P<major>\d+)\.(?P<minor>\d+)\.(?P<patch>\d+)\.(?P<build>\d+)
serialize =
    {major}.{minor}.{patch}.{build}
    {major}.{minor}.{patch}

[bumpversion:part:build]

[bumpversion:file:setup.py]

error

Attempting to increment part 'minor'
Values are now: build=0, major=0, minor=1, patch=0
Dry run active, won't touch any files.
Evaluating 'parse' option: '(?P<major>\d+)\.(?P<minor>\d+)\.(?P<patch>\d+)\.(?P<build>\d+)' does not parse current version '0.1.0'
New version will be '0.1.0'
Asserting files setup.py contain the version string...
Traceback (most recent call last):
  File "/usr/local/bin/bumpversion", line 8, in <module>
    sys.exit(main())
  File "/usr/local/lib/python3.8/site-packages/bumpversion/cli.py", line 125, in main
    _replace_version_in_files(files, current_version, new_version, args.dry_run, context)
  File "/usr/local/lib/python3.8/site-packages/bumpversion/cli.py", line 624, in _replace_version_in_files
    f.replace(current_version, new_version, context, dry_run)
  File "/usr/local/lib/python3.8/site-packages/bumpversion/utils.py", line 112, in replace
    context["new_version"] = self._versionconfig.serialize(new_version, context)
  File "/usr/local/lib/python3.8/site-packages/bumpversion/version_part.py", line 278, in serialize
    version, self._choose_serialize_format(version, context), context
  File "/usr/local/lib/python3.8/site-packages/bumpversion/version_part.py", line 257, in _choose_serialize_format
    self._serialize(
  File "/usr/local/lib/python3.8/site-packages/bumpversion/version_part.py", line 201, in _serialize
    for k in version:
TypeError: 'NoneType' object is not iterable

what's wrong with my config file?

peritus / bumpversion

help need: error while serialize following pattern (?P<major>\d+)\.(?P<minor>\d+)\.(?P<patch>\d+)\.(?P<build>\d+) #213