jupyter AttributeError: module 'dateutil.tz' has no attribute 'UTC'

[Vincent Delecroix]

Hello,

While running Jupyter with 9.1.beta6, the kernel is complaining
with dateutil (see below). Upgrading dateutil to 2.8.1 fixes
the problem. Please review

https://trac.sagemath.org/ticket/29268

Vincent


Traceback (most recent call last):
File
"/opt/sage/local/lib/python3.7/site-packages/ipykernel/kernelbase.py",
line 206, in dispatch_shell
msg = self.session.deserialize(msg, content=True, copy=False)
File
"/opt/sage/local/lib/python3.7/site-packages/jupyter_client/session.py",
line 927, in deserialize
message['header'] = extract_dates(header)
File
"/opt/sage/local/lib/python3.7/site-packages/jupyter_client/jsonutil.py",
line 67, in extract_dates
new_obj[k] = extract_dates(v)
File
"/opt/sage/local/lib/python3.7/site-packages/jupyter_client/jsonutil.py",
line 72, in extract_dates
obj = parse_date(obj)
File
"/opt/sage/local/lib/python3.7/site-packages/jupyter_client/jsonutil.py",
line 58, in parse_date
dt = _dateutil_parse(s)
File
"/opt/sage/local/lib/python3.7/site-packages/dateutil/parser/_parser.py",
line 1374, in parse
return DEFAULTPARSER.parse(timestr, **kwargs)
File
"/opt/sage/local/lib/python3.7/site-packages/dateutil/parser/_parser.py",
line 660, in parse
ret = self._build_tzaware(ret, res, tzinfos)
File
"/opt/sage/local/lib/python3.7/site-packages/dateutil/parser/_parser.py",
line 1201, in _build_tzaware
aware = naive.replace(tzinfo=tz.UTC)
AttributeError: module 'dateutil.tz' has no attribute 'UTC'

Note that our dateutil version is slightly outdated (2.5.3 instead
of 2.8.1).