由于构建依赖项 Python 2.7 不兼容，Pip 安装失败

如何解决由于构建依赖项 Python 2.7 不兼容，Pip 安装失败

我正在尝试使用 pypy-2.7-buster Docker 映像构建我的旧项目。 一些需求需要在容器内部的安装过程中构建。

当我的依赖项之一需要 setuptools 来构建自身时，问题出现了，它们在 pyproject.toml 或 setup.py 中的指定版本太松散并且它获取了 setuptools-57.something 而不是与 Python 2.7 兼容。

要求.txt

setuptools==44.1.1
numpy==1.16.6
cryptography==3.3.1

这是一个发生在 cryptography-3.3.1 的情况（第 15 和 16 行给出了它）：

1   Requirement already satisfied: setuptools==44.1.1 in /opt/pypy/site-packages (from -c constraints.txt (line 1)) (44.1.1)
2   Collecting numpy==1.16.6
3    Downloading .../numpy-1.16.6.zip (5.1 MB)
4   Collecting cryptography==3.3.1
5     Downloading ...cryptography-3.3.1.tar.gz (539 kB)
6     Installing build dependencies: started
7     Installing build dependencies: finished with status 'error'
8     ERROR: Command errored out with exit status 1:
9      command: /opt/pypy/bin/pypy /opt/pypy/site-packages/pip install --ignore-installed --no-user --prefix /tmp/pip-build-env-rDC5lF/overlay --no-warn-script-location --no-binary :none: --only-binary :none: -i repo --trusted-host host -- 'setuptools>=40.6.0' wheel 'cffi>=1.12; platform_python_implementation != '"'"'PyPy'"'"''
10         cwd: None
11    Complete output (34 lines):
12     DEPRECATION: pip 21.0 will drop support for Python 2.7 in January 2021. More details about Python 2 support in pip can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support pip 21.0 will remove support for this functionality.
13    Looking in indexes: repo
14    Ignoring cffi: markers 'platform_python_implementation != "PyPy"' don't match your environment
15    Collecting setuptools>=40.6.0
16      Downloading repo/setuptools-57.4.0.tar.gz (2.1 MB)
17      Installing build dependencies: started
18      Installing build dependencies: finished with status 'done'
19      Getting requirements to build wheel: started
20      Getting requirements to build wheel: finished with status 'error'
21      ERROR: Command errored out with exit status 1:
22       command: /opt/pypy/bin/pypy /opt/pypy/site-packages/pip/_vendor/pep517/_in_process.py get_requires_for_build_wheel /tmp/tmpXomGVX
23           cwd: /tmp/pip-install-8S7wKA/setuptools
24      Complete output (19 lines):
25      Traceback (most recent call last):
26        File "/opt/pypy/site-packages/pip/_vendor/pep517/_in_process.py",line 280,in <module>
27          main()
28        File "/opt/pypy/site-packages/pip/_vendor/pep517/_in_process.py",line 263,in main
29          json_out['return_val'] = hook(**hook_input['kwargs'])
30        File "/opt/pypy/site-packages/pip/_vendor/pep517/_in_process.py",line 108,in get_requires_for_build_wheel
31          backend = _build_backend()
32        File "/opt/pypy/site-packages/pip/_vendor/pep517/_in_process.py",line 86,in _build_backend
33          obj = import_module(mod_path)
34        File "/opt/pypy/lib-python/2.7/importlib/__init__.py",line 37,in import_module
35          __import__(name)
36        File "/tmp/pip-install-8S7wKA/setuptools/setuptools/__init__.py",line 16,in <module>
37          import setuptools.version
38        File "/tmp/pip-install-8S7wKA/setuptools/setuptools/version.py",line 1,in <module>
39          import pkg_resources
40        File "/tmp/pip-install-8S7wKA/setuptools/pkg_resources/__init__.py",line 1367
41          raise SyntaxError(e) from e
42                               ^
43      SyntaxError: invalid syntax
44      ----------------------------------------
45    ERROR: Command errored out with exit status 1: /opt/pypy/bin/pypy /opt/pypy/site-packages/pip/_vendor/pep517/_in_process.py get_requires_for_build_wheel /tmp/tmpXomGVX Check the logs for full command output.
46    ----------------------------------------
47w  ERROR: Command errored out with exit status 1: /opt/pypy/bin/pypy /opt/pypy/site-packages/pip install --ignore-installed --no-user --prefix /tmp/pip-build-env-rDC5lF/overlay --no-warn-script-location --no-binary :none: --only-binary :none: -i repo --trusted-host host -- 'setuptools>=40.6.0' wheel 'cffi>=1.12; platform_python_implementation != '"'"'PyPy'"'"'' Check the logs for full command output.

在 pyproject.toml 源代码的 cryptography-3.3.1 中，有这个：

requires = ["setuptools>=40.6.0"...

所以它会忽略它已经安装的 setuptools-44.1.1 并去获取与 Python 2.7 不兼容的最新版本。

我看到它在安装构建依赖项时运行的命令有一个 --ignore-installed 标志，可以覆盖吗？

我尝试更改源 PKG-INFO，将此自定义版本上传到我的存储库，并且成功了。 问题是，它发生在多个地方（pandas、PyYAML ......），并且为每个需求做自定义版本感觉很糟糕。 :(

还尝试了一些 pip 标志来覆盖它，但没有任何帮助。

谢谢！