“ pip install -e”仅在MacOS上找不到alabaster == 0.7.12

Question

python3.7和pip18。 macos 10.13 setup.py是：

from setuptools import setup, find_packages

setup(
    name='proxy-tools',
    version='1.0.0',
    packages=find_packages(),
    include_package_data=True,
    install_requires=[
        'alabaster==0.7.12',
    ],
)

和鸡蛋

cat requires.txt 
alabaster==0.7.12

我运行pip install -e .

Collecting alabaster==0.7.12 (from proxy-tools==1.0.0)
  Could not find a version that satisfies the requirement alabaster==0.7.12 (from proxy-tools==1.0.0) (from versions: )
No matching distribution found for alabaster==0.7.12 (from proxy-tools==1.0.0)

这很奇怪，因为运行pip search alabaster，我可以看到它列出的版本是0.7.12