我一直在尝试在我的 Raspberry Pi Zero 上安装包“flask-ask”。但是，尝试安装依赖项“cryptography”时出现问题：
Downloading/unpacking cryptography
Downloading cryptography-2.2.2.tar.gz (443kB): 443kB downloaded
Running setup.py (path:/tmp/pip-build-wg353po4/cryptography/setup.py) egg_info for package cryptography
Traceback (most recent call last):
File "<string>", line 17, in <module>
File "/tmp/pip-build-wg353po4/cryptography/setup.py", line 28, in <module>
"cryptography requires setuptools 18.5 or newer, please upgrade to a "
RuntimeError: cryptography requires setuptools 18.5 or newer, please upgrade to a newer version of setuptools
Complete output from command python setup.py egg_info:
Traceback (most recent call last):
File "<string>", line 17, in <module>
File "/tmp/pip-build-wg353po4/cryptography/setup.py", line 28, in <module>
"cryptography requires setuptools 18.5 or newer, please upgrade to a "
RuntimeError: cryptography requires setuptools 18.5 or newer, please upgrade to a newer version of setuptools
----------------------------------------
Cleaning up...
Command python setup.py egg_info failed with error code 1 in /tmp/pip-build-wg353po4/cryptography
Storing debug log for failure in /home/pi/.pip/pip.log
（这些日志来自尝试自行安装密码学，但在安装烧瓶询问时出现相同的错误）
我已经尝试pip3 install -U setuptools升级它，但这不起作用：
pi@raspberrypi:~ $ pip3 install -U setuptools
Downloading/unpacking setuptools from https://files.pythonhosted.org/packages/7f/e1/820d941153923aac1d49d7fc37e17b6e73bfbd2904959fffbad77900cf92/setuptools-39.2.0-py2.py3-none-any.whl#sha256=8fca9275c89964f13da985c3656cb00ba029d7f3916b37990927ffdf264e7926
Downloading setuptools-39.2.0-py2.py3-none-any.whl (567kB): 567kB downloaded
Installing collected packages: setuptools
Found existing installation: setuptools 5.5.1
Not uninstalling setuptools at /usr/lib/python3/dist-packages, owned by OS
Can't roll back setuptools; was not uninstalled
Cleaning up...
Exception:
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/pip/basecommand.py", line 122, in main
status = self.run(options, args)
File "/usr/lib/python3/dist-packages/pip/commands/install.py", line 295, in run
requirement_set.install(install_options, global_options, root=options.root_path)
File "/usr/lib/python3/dist-packages/pip/req.py", line 1436, in install
requirement.install(install_options, global_options, *args, **kwargs)
File "/usr/lib/python3/dist-packages/pip/req.py", line 672, in install
self.move_wheel_files(self.source_dir, root=root)
File "/usr/lib/python3/dist-packages/pip/req.py", line 902, in move_wheel_files
pycompile=self.pycompile,
File "/usr/lib/python3/dist-packages/pip/wheel.py", line 214, in move_wheel_files
clobber(source, lib_dir, True)
File "/usr/lib/python3/dist-packages/pip/wheel.py", line 208, in clobber
shutil.copy2(srcfile, destfile)
File "/usr/lib/python3.4/shutil.py", line 244, in copy2
copyfile(src, dst, follow_symlinks=follow_symlinks)
File "/usr/lib/python3.4/shutil.py", line 108, in copyfile
with open(dst, 'wb') as fdst:
PermissionError: [Errno 13] Permission denied: '/usr/local/lib/python3.4/dist-packages/easy_install.py'
Storing debug log for failure in /home/pi/.pip/pip.log
所以我该怎么做？我已经对各种不同的事情进行了很多谷歌搜索，并且我看到其他人在 Pi 上遇到密码学问题，但不是这个特定问题。
编辑：好的，所以我现在已经完成pip install --user -U setuptools了，而且效果很好。现在我得到了一个完全不同的错误：
running install_egg_info
running egg_info
creating lib/PyYAML.egg-info
writing lib/PyYAML.egg-info/PKG-INFO
writing top-level names to lib/PyYAML.egg-info/top_level.txt
writing dependency_links to lib/PyYAML.egg-info/dependency_links.txt
writing manifest file 'lib/PyYAML.egg-info/SOURCES.txt'
reading manifest file 'lib/PyYAML.egg-info/SOURCES.txt'
writing manifest file 'lib/PyYAML.egg-info/SOURCES.txt'
Copying lib/PyYAML.egg-info to /home/pi/.local/lib/python2.7/site-packages/PyYAML-3.12$
running install_scripts
writing list of installed files to '/tmp/pip-XYXo6X-record/install-record.txt'
Could not find .egg-info directory in install record for PyYAML==3.12 (from flask-ask)
Running setup.py install for cryptography
Running command /usr/bin/python -c "import setuptools, tokenize;__file__='/tmp/pip-bui$
Package libffi was not found in the pkg-config search path.
Perhaps you should add the directory containing `libffi.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libffi' found
Package libffi was not found in the pkg-config search path.
Perhaps you should add the directory containing `libffi.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libffi' found
Package libffi was not found in the pkg-config search path.
Perhaps you should add the directory containing `libffi.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libffi' found
Package libffi was not found in the pkg-config search path.
Perhaps you should add the directory containing `libffi.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libffi' found
Package libffi was not found in the pkg-config search path.
Perhaps you should add the directory containing `libffi.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libffi' found
c/_cffi_backend.c:2:20: fatal error: Python.h: No such file or directory
#include <Python.h>
^
compilation terminated.
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/tmp/pip-build-2gl72v/cryptography/setup.py", line 319, in <module>
**keywords_with_side_effects(sys.argv)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/__init__.py", line 128,$
_install_setup_requires(attrs)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/__init__.py", line 123,$
dist.fetch_build_eggs(dist.setup_requires)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/dist.py", line 514, in $
replace_conflicting=True,
File "/home/pi/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 7$
replace_conflicting=replace_conflicting
File "/home/pi/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 1$
return self.obtain(req, installer)
File "/home/pi/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 1$
return installer(requirement)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/dist.py", line 581, in $
return cmd.easy_install(req)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/command/easy_install.py$
return self.install_item(spec, dist.location, tmpdir, deps)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/command/easy_install.py$
dists = self.install_eggs(spec, download, tmpdir)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/command/easy_install.py$
return self.build_and_install(setup_script, setup_base)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/command/easy_install.py$
self.run_setup(setup_script, setup_base, args)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/command/easy_install.py$
raise DistutilsError("Setup script exited with %s" % (v.args[0],))
distutils.errors.DistutilsError: Setup script exited with error: command 'arm-linux-gn$
Complete output from command /usr/bin/python -c "import setuptools, tokenize;__file__=$
Package libffi was not found in the pkg-config search path.
Perhaps you should add the directory containing `libffi.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libffi' found
Package libffi was not found in the pkg-config search path.
Perhaps you should add the directory containing `libffi.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libffi' found
Package libffi was not found in the pkg-config search path.
Perhaps you should add the directory containing `libffi.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libffi' found
Package libffi was not found in the pkg-config search path.
Perhaps you should add the directory containing `libffi.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libffi' found
Package libffi was not found in the pkg-config search path.
Perhaps you should add the directory containing `libffi.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libffi' found
c/_cffi_backend.c:2:20: fatal error: Python.h: No such file or directory
#include <Python.h>
^
compilation terminated.
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/tmp/pip-build-2gl72v/cryptography/setup.py", line 319, in <module>
**keywords_with_side_effects(sys.argv)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/__init__.py", line 128, in $
_install_setup_requires(attrs)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/__init__.py", line 123, in $
dist.fetch_build_eggs(dist.setup_requires)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/dist.py", line 514, in fetc$
replace_conflicting=True,
File "/home/pi/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 770, $
replace_conflicting=replace_conflicting
File "/home/pi/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 1053,$
return self.obtain(req, installer)
File "/home/pi/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 1065,$
return installer(requirement)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/dist.py", line 581, in fetc$
return cmd.easy_install(req)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/command/easy_install.py", l$
return self.install_item(spec, dist.location, tmpdir, deps)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/command/easy_install.py", l$
dists = self.install_eggs(spec, download, tmpdir)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/command/easy_install.py", l$
return self.build_and_install(setup_script, setup_base)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/command/easy_install.py", l$
self.run_setup(setup_script, setup_base, args)
File "/home/pi/.local/lib/python2.7/site-packages/setuptools/command/easy_install.py", l$
raise DistutilsError("Setup script exited with %s" % (v.args[0],))
distutils.errors.DistutilsError: Setup script exited with error: command 'arm-linux-gnueab$
----------------------------------------
Cleaning up...
Command /usr/bin/python -c "import setuptools, tokenize;__file__='/tmp/pip-build-2gl72v/cr$
Exception information:
Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/pip/basecommand.py", line 122, in main
status = self.run(options, args)
File "/usr/lib/python2.7/dist-packages/pip/commands/install.py", line 295, in run
requirement_set.install(install_options, global_options, root=options.root_path)
File "/usr/lib/python2.7/dist-packages/pip/req.py", line 1436, in install
requirement.install(install_options, global_options, *args, **kwargs)
File "/usr/lib/python2.7/dist-packages/pip/req.py", line 707, in install
cwd=self.source_dir, filter_stdout=self._filter_install, show_stdout=False)
File "/usr/lib/python2.7/dist-packages/pip/util.py", line 716, in call_subprocess
% (command_desc, proc.returncode, cwd))
InstallationError: Command /usr/bin/python -c "import setuptools, tokenize;__file__='/tmp/$
我不知道为什么会发生这种情况。