issue_comments: 537953053

I'm getting a crash in readthedocs because of versioneer: https://readthedocs.org/projects/crusaderky-xarray/builds/9748865/

In the RTD CI, versioneer incorrectly sets the version as 0+untagged.111.g6d60700, which while it is compliant to PEP-440, it obviously fails a minimum version check in pandas.DataFrame.to_xarray. On top of this, there's a bug in distutils (!!!) that causes an ugly crash instead of a clean error message:

``` pandas/compat/_optional.py(100)import_optional_dependency()

 98     if minimum_version:
 99         version = _get_version(module)

--> 100 if distutils.version.LooseVersion(version) < minimum_version: 101 assert on_version in {"warn", "raise", "ignore"}

``` if distutils.version.LooseVersion(version) < minimum_version:

To replicate locally: manually

``` xarray: 0+untagged.111.g6d60700 [...]

---

Exception in /home/docs/checkouts/readthedocs.org/user_builds/crusaderky-xarray/checkouts/mindeps/doc/pandas.rst at block ending on line 105 Specify :okexcept: as an option in the ipython:: block to suppress this message

---

TypeError Traceback (most recent call last) <ipython-input-10-7f86783d8836> in <module> ----> 1 s[::2].to_xarray()

~/checkouts/readthedocs.org/user_builds/crusaderky-xarray/conda/mindeps/lib/python3.7/site-packages/pandas/core/generic.py in to_xarray(self) 2904 speed (date, animal) int64 350 18 361 15 2905 """ -> 2906 xarray = import_optional_dependency("xarray") 2907 2908 if self.ndim == 1:

~/checkouts/readthedocs.org/user_builds/crusaderky-xarray/conda/mindeps/lib/python3.7/site-packages/pandas/compat/_optional.py in import_optional_dependency(name, extra, raise_on_missing, on_version) 98 if minimum_version: 99 version = _get_version(module) --> 100 if distutils.version.LooseVersion(version) < minimum_version: 101 assert on_version in {"warn", "raise", "ignore"} 102 msg = version_message.format(

~/checkouts/readthedocs.org/user_builds/crusaderky-xarray/conda/mindeps/lib/python3.7/distutils/version.py in lt(self, other) 50 51 def lt(self, other): ---> 52 c = self._cmp(other) 53 if c is NotImplemented: 54 return c

~/checkouts/readthedocs.org/user_builds/crusaderky-xarray/conda/mindeps/lib/python3.7/distutils/version.py in _cmp(self, other) 335 if self.version == other.version: 336 return 0 --> 337 if self.version < other.version: 338 return -1 339 if self.version > other.version:

TypeError: '<' not supported between instances of 'str' and 'int' ```