问题：Could not find a version that satisfies the requirement setuptools_scm

问题描述：通过pip安装paddlehub时，报如下错误

ERROR: Command errored out with exit status 1:
     command: /root/anaconda3/bin/python -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-on3na72o/seqeval/setup.py'"'"'; __file__='"'"'/tmp/pip-install-on3na72o/seqeval/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base /tmp/pip-pip-egg-info-kx8cgfp0
         cwd: /tmp/pip-install-on3na72o/seqeval/
    Complete output (33 lines):
    WARNING: The repository located at mirrors.cloud.aliyuncs.com is not a trusted or secure host and is being ignored. If this repository is available via HTTPS we recommend you use HTTPS instead, otherwise you may silence this warning and allow it anyway with '--trusted-host mirrors.cloud.aliyuncs.com'.
    ERROR: Could not find a version that satisfies the requirement setuptools_scm (from versions: none)
    ERROR: No matching distribution found for setuptools_scm
    Traceback (most recent call last):
      File "/root/anaconda3/lib/python3.8/site-packages/setuptools/installer.py", line 126, in fetch_build_egg
        subprocess.check_call(cmd)
      File "/root/anaconda3/lib/python3.8/subprocess.py", line 364, in check_call
        raise CalledProcessError(retcode, cmd)
    subprocess.CalledProcessError: Command '['/root/anaconda3/bin/python', '-m', 'pip', '--disable-pip-version-check', 'wheel', '--no-deps', '-w', '/tmp/tmpsoxvs315', '--quiet', '--index-url', 'http://mirrors.cloud.aliyuncs.com/pypi/simple/', 'setuptools_scm']' returned non-zero exit status 1.

根据ERROR行日志解决方案如下：

pip install setuptools-scm

安装完成后重新执行pip install即可

pip install paddlehub==2.1.0 --upgrade -i https://mirror.baidu.com/pypi/simple