【发布时间】：2020-10-07 19:17:41
【问题描述】：
我最近更新到 Python 3.9。在尝试安装依赖项为我的 Discord 服务器编写机器人时，Windows Powershell 控制台显示错误。包括错误在内的日志如下。我不知道该怎么办。任何帮助，将不胜感激。我在 Windows 10 上。
Collecting discord.py
Using cached discord.py-1.5.0-py3-none-any.whl (699 kB)
Collecting aiohttp<3.7.0,>=3.6.0
Using cached aiohttp-3.6.2-py3-none-any.whl (441 kB)
Collecting multidict<5.0,>=4.5
Using cached multidict-4.7.6.tar.gz (50 kB)
Installing build dependencies: started
Installing build dependencies: finished with status 'done'
Getting requirements to build wheel: started
Getting requirements to build wheel: finished with status 'done'
Preparing wheel metadata: started
Preparing wheel metadata: finished with status 'done'
Collecting attrs>=17.3.0
Using cached attrs-20.2.0-py2.py3-none-any.whl (48 kB)
Collecting yarl<2.0,>=1.0
Using cached yarl-1.6.0.tar.gz (175 kB)
Installing build dependencies: started
Installing build dependencies: finished with status 'done'
Getting requirements to build wheel: started
Getting requirements to build wheel: finished with status 'done'
Preparing wheel metadata: started
Preparing wheel metadata: finished with status 'done'
Collecting async-timeout<4.0,>=3.0
Using cached async_timeout-3.0.1-py3-none-any.whl (8.2 kB)
Collecting chardet<4.0,>=2.0
Using cached chardet-3.0.4-py2.py3-none-any.whl (133 kB)
Collecting idna>=2.0
Using cached idna-2.10-py2.py3-none-any.whl (58 kB)
Building wheels for collected packages: multidict, yarl
Building wheel for multidict (PEP 517): started
Building wheel for multidict (PEP 517): finished with status 'error'
pip : ERROR: Command errored out with exit status 1:
At line:1 char:1
+ pip install -U discord.py 2>&1 | tee -filepath c:\users\drago\desktop ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: ( ERROR: Comman... exit status 1::String) [], RemoteException
+ FullyQualifiedErrorId : NativeCommandError
command: 'c:\users\drago\appdata\local\programs\python\python39\python.exe'
'c:\users\drago\appdata\local\programs\python\python39\lib\site-packages\pip\_vendor\pep517\_in_process.py'
build_wheel 'C:\Users\drago\AppData\Local\Temp\tmpqtrgsff9'
cwd: C:\Users\drago\AppData\Local\Temp\pip-install-dtjlyufp\multidict
Complete output (44 lines):
**********************
* Accellerated build *
**********************
running bdist_wheel
running build
running build_py
creating build
creating build\lib.win-amd64-3.9
creating build\lib.win-amd64-3.9\multidict
copying multidict\_abc.py -> build\lib.win-amd64-3.9\multidict
copying multidict\_compat.py -> build\lib.win-amd64-3.9\multidict
copying multidict\_multidict_base.py -> build\lib.win-amd64-3.9\multidict
copying multidict\_multidict_py.py -> build\lib.win-amd64-3.9\multidict
copying multidict\__init__.py -> build\lib.win-amd64-3.9\multidict
running egg_info
writing multidict.egg-info\PKG-INFO
writing dependency_links to multidict.egg-info\dependency_links.txt
writing top-level names to multidict.egg-info\top_level.txt
reading manifest file 'multidict.egg-info\SOURCES.txt'
reading manifest template 'MANIFEST.in'
warning: no previously-included files matching '*.pyc' found anywhere in distribution
warning: no previously-included files found matching 'multidict\_multidict.html'
warning: no previously-included files found matching 'multidict\*.so'
warning: no previously-included files found matching 'multidict\*.pyd'
warning: no previously-included files found matching 'multidict\*.pyd'
no previously-included directories found matching 'docs\_build'
writing manifest file 'multidict.egg-info\SOURCES.txt'
copying multidict\__init__.pyi -> build\lib.win-amd64-3.9\multidict
copying multidict\_multidict.c -> build\lib.win-amd64-3.9\multidict
copying multidict\py.typed -> build\lib.win-amd64-3.9\multidict
creating build\lib.win-amd64-3.9\multidict\_multilib
copying multidict\_multilib\defs.h -> build\lib.win-amd64-3.9\multidict\_multilib
copying multidict\_multilib\dict.h -> build\lib.win-amd64-3.9\multidict\_multilib
copying multidict\_multilib\istr.h -> build\lib.win-amd64-3.9\multidict\_multilib
copying multidict\_multilib\iter.h -> build\lib.win-amd64-3.9\multidict\_multilib
copying multidict\_multilib\pair_list.h -> build\lib.win-amd64-3.9\multidict\_multilib
copying multidict\_multilib\views.h -> build\lib.win-amd64-3.9\multidict\_multilib
running build_ext
building 'multidict._multidict' extension
creating build\temp.win-amd64-3.9
creating build\temp.win-amd64-3.9\Release
creating build\temp.win-amd64-3.9\Release\multidict
cl.exe /c /nologo /Ox /W3 /GL /DNDEBUG /MD -Ic:\users\drago\appdata\local\programs\python\python39\include
-Ic:\users\drago\appdata\local\programs\python\python39\include /Tcmultidict/_multidict.c
/Fobuild\temp.win-amd64-3.9\Release\multidict/_multidict.obj -O2
error: command 'cl.exe' failed: None
----------------------------------------
ERROR: Failed building wheel for multidict
Building wheel for yarl (PEP 517): started
Building wheel for yarl (PEP 517): finished with status 'error'
ERROR: Command errored out with exit status 1:
command: 'c:\users\drago\appdata\local\programs\python\python39\python.exe'
'c:\users\drago\appdata\local\programs\python\python39\lib\site-packages\pip\_vendor\pep517\_in_process.py'
build_wheel 'C:\Users\drago\AppData\Local\Temp\tmpl23ue1yv'
cwd: C:\Users\drago\AppData\Local\Temp\pip-install-dtjlyufp\yarl
Complete output (39 lines):
**********************
* Accellerated build *
**********************
running bdist_wheel
running build
running build_py
creating build
creating build\lib.win-amd64-3.9
creating build\lib.win-amd64-3.9\yarl
copying yarl\_quoting.py -> build\lib.win-amd64-3.9\yarl
copying yarl\_quoting_py.py -> build\lib.win-amd64-3.9\yarl
copying yarl\_url.py -> build\lib.win-amd64-3.9\yarl
copying yarl\__init__.py -> build\lib.win-amd64-3.9\yarl
running egg_info
writing yarl.egg-info\PKG-INFO
writing dependency_links to yarl.egg-info\dependency_links.txt
writing requirements to yarl.egg-info\requires.txt
writing top-level names to yarl.egg-info\top_level.txt
reading manifest file 'yarl.egg-info\SOURCES.txt'
reading manifest template 'MANIFEST.in'
warning: no previously-included files matching '*.pyc' found anywhere in distribution
warning: no previously-included files matching '*.cache' found anywhere in distribution
warning: no previously-included files found matching 'yarl\*.html'
warning: no previously-included files found matching 'yarl\*.so'
warning: no previously-included files found matching 'yarl\*.pyd'
no previously-included directories found matching 'docs\_build'
writing manifest file 'yarl.egg-info\SOURCES.txt'
copying yarl\__init__.pyi -> build\lib.win-amd64-3.9\yarl
copying yarl\_quoting_c.c -> build\lib.win-amd64-3.9\yarl
copying yarl\_quoting_c.pyi -> build\lib.win-amd64-3.9\yarl
copying yarl\_quoting_c.pyx -> build\lib.win-amd64-3.9\yarl
copying yarl\py.typed -> build\lib.win-amd64-3.9\yarl
running build_ext
building 'yarl._quoting_c' extension
creating build\temp.win-amd64-3.9
creating build\temp.win-amd64-3.9\Release
creating build\temp.win-amd64-3.9\Release\yarl
cl.exe /c /nologo /Ox /W3 /GL /DNDEBUG /MD -Ic:\users\drago\appdata\local\programs\python\python39\include
-Ic:\users\drago\appdata\local\programs\python\python39\include /Tcyarl/_quoting_c.c
/Fobuild\temp.win-amd64-3.9\Release\yarl/_quoting_c.obj
error: command 'cl.exe' failed: None
----------------------------------------
ERROR: Failed building wheel for yarl
Failed to build multidict yarl
ERROR: Could not build wheels for multidict, yarl which use PEP 517 and cannot be installed directly
谢谢大家。我对 Python 的了解仍然非常有限，所以如果一个包“无法直接安装”，我不知道该如何解决。
【问题讨论】：
-
python 3.9 还不能开箱即用。
multidict还没有为 3.9 准备好轮子：github.com/aio-libs/multidict/issues/534。yarl没有为 3.9 准备好轮子：github.com/aio-libs/yarl/issues/526，当 pip 查找编译器cl.exe时，它没有找到并失败。 -
如果您有兴趣继续使用 python 3.9 并想尝试自己编译它们：stackoverflow.com/questions/41724445/… 否则只需使用 3.8 版本：python.org/downloads/release/python-386
标签： python-3.x powershell discord.py