构建 pygdal 时出错：未知的分发选项：“use_2to3_fixers”和“use_2to3_exclude_fixers”

下面提供解决方案：

在 Ubuntu 20.04 上构建 pygdal 时开始出现错误：

# Command
python3 -m pip install --no-cache-dir pygdal==3.0.4.*

产生以下输出

Collecting pygdal==3.0.4.*
  Downloading pygdal-3.0.4.6.tar.gz (458 kB)
     |████████████████████████████████| 458 kB 3.7 MB/s 
    ERROR: Command errored out with exit status 1:
     command: /usr/bin/python3 -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-we7e68ge/pygdal/setup.py'"'"'; __file__='"'"'/tmp/pip-install-we7e68ge/pygdal/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-install-we7e68ge/pygdal/pip-egg-info
         cwd: /tmp/pip-install-we7e68ge/pygdal/
    Complete output (5 lines):
    /usr/lib/python3.8/distutils/dist.py:274: UserWarning: Unknown distribution option: 'use_2to3_fixers'
      warnings.warn(msg)
    /usr/lib/python3.8/distutils/dist.py:274: UserWarning: Unknown distribution option: 'use_2to3_exclude_fixers'
      warnings.warn(msg)
    error in pygdal setup command: use_2to3 is invalid.
    ----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.

重现该错误的步骤是：

# Commands to run inside of running Ubuntu 20.04 docker instance
apt update
# install python3.8 and link python3 to this version - these next 2 steps may not be needed for your scenario
apt install -y python3.8
ln -s /usr/bin/python3.8 /usr/bin/python3
# done installing python3.8
apt install -y python3-pip
apt-get install -y python3-gdal gdal-bin libgdal-dev gcc g++ python3.8-dev git
python3 -m pip install --upgrade --no-cache-dir setuptools==58.0.4
python3 -m pip install --upgrade --no-cache-dir numpy wheel requests
python3 -m pip install --no-cache-dir pygdal==3.0.4.*

解决方案是安装旧版本的 setuptools。指定版本 58.0.2 及更早版本会导致构建成功。我只回到了 58.0.0 来解决这个问题，但这是我第一次看到这个问题，所以早期版本应该也能工作。

# Replace the above installation of setuptools with the following
python3 -m pip install --upgrade --no-cache-dir setuptools==58.0.2

用于安装 GDAL 版本 3.0.4。就我而言，我已将 setuptools 从 58.2.0 降级到 57.5.0 版本。 使用命令：

pip3 install setuptools==57.5.0