Windows install errors

[July0928]

******I install g2o by "pip install -U g2o-python", and the result is successful. ******

"Looking in indexes: http://mirrors.aliyun.com/pypi/simple/
Collecting g2o-python
Downloading http://mirrors.aliyun.com/pypi/packages/9e/84/f7e06c42ec8965d5375eb7c8acd86d3514a8519190a042571b1797a6b98f/g2o_python-0.0.12-cp38-cp38-win_amd64.whl (21.3 MB)
---------------------------------------- 21.3/21.3 MB 3.3 MB/s eta 0:00:00
Requirement already satisfied: scikit-build in c:\app\anaconda3\envs\superglue_3.8\lib\site-packages (from g2o-python) (0.17.0)
Requirement already satisfied: numpy in c:\app\anaconda3\envs\superglue_3.8\lib\site-packages (from g2o-python) (1.19.3)
Requirement already satisfied: distro in c:\app\anaconda3\envs\superglue_3.8\lib\site-packages (from scikit-build->g2o-python) (1.8.0)
Requirement already satisfied: packaging in c:\app\anaconda3\envs\superglue_3.8\lib\site-packages (from scikit-build->g2o-python) (21.3)
Requirement already satisfied: wheel>=0.32.0 in c:\app\anaconda3\envs\superglue_3.8\lib\site-packages (from scikit-build->g2o-python) (0.37.1)
Requirement already satisfied: tomli in c:\app\anaconda3\envs\superglue_3.8\lib\site-packages (from scikit-build->g2o-python) (2.0.1)
Requirement already satisfied: setuptools>=42.0.0 in c:\app\anaconda3\envs\superglue_3.8\lib\site-packages (from scikit-build->g2o-python) (63.2.0)
Requirement already satisfied: pyparsing!=3.0.5,>=2.0.2 in c:\app\anaconda3\envs\superglue_3.8\lib\site-packages (from packaging->scikit-build->g2o-python) (3.0.9)
Installing collected packages: g2o-python
Successfully installed g2o-python-0.0.12"

But when i use it , it goes wrong like "ModuleNotFoundError: No module named 'g2o.contrib' ", and when i search the "g2o" in sitepackages, there are init.py, pycache, and g2opy.cp38-win_amd64.pyd. And there is only one line in init.py, which is "from .g2opy import * # noqa: F401"

windows10, python 3.8