Python 实用宝典

Question 1

When I try to install the Cryptography package for Python through either pip install cryptography or by downloading the package from their site and running python setup.py, I get the following error:

D:\Anaconda\Scripts\pip-script.py run on 02/27/14 16:13:17
Downloading/unpacking cryptography
  Getting page https://pypi.python.org/simple/cryptography/
  URLs to search for versions for cryptography:
  * https://pypi.python.org/simple/cryptography/
  Analyzing links from page https://pypi.python.org/simple/cryptography/
    Skipping https://pypi.python.org/packages/cp26/c/cryptography/cryptography-0.2-cp26-none-win32.whl#md5=13e5c4b19520e7dc6f07c6502b3f74e2 (from https://pypi.python.org/simple/cryptography/) because it is not compatible with this Python
    Skipping https://pypi.python.org/packages/cp26/c/cryptography/cryptography-0.2.1-cp26-none-win32.whl#md5=00e733648ee5cdb9e58876238b1328f8 (from https://pypi.python.org/simple/cryptography/) because it is not compatible with this Python
    Skipping https://pypi.python.org/packages/cp27/c/cryptography/cryptography-0.2-cp27-none-win32.whl#md5=013ccafa6a5a3ea92c73f2c1c4879406 (from https://pypi.python.org/simple/cryptography/) because it is not compatible with this Python
    Skipping https://pypi.python.org/packages/cp27/c/cryptography/cryptography-0.2.1-cp27-none-win32.whl#md5=127d6a5dc687250721f892d55720a06c (from https://pypi.python.org/simple/cryptography/) because it is not compatible with this Python
    Skipping https://pypi.python.org/packages/cp32/c/cryptography/cryptography-0.2-cp32-none-win32.whl#md5=051424a36e91039807b72f112333ded3 (from https://pypi.python.org/simple/cryptography/) because it is not compatible with this Python
    Skipping https://pypi.python.org/packages/cp32/c/cryptography/cryptography-0.2.1-cp32-none-win32.whl#md5=53f6f57db8e952d64283baaa14cbde3d (from https://pypi.python.org/simple/cryptography/) because it is not compatible with this Python
    Skipping https://pypi.python.org/packages/cp33/c/cryptography/cryptography-0.2-cp33-none-win32.whl#md5=302812c1c1a035cf9ba3292f8dbf3f9e (from https://pypi.python.org/simple/cryptography/) because it is not compatible with this Python
    Skipping https://pypi.python.org/packages/cp33/c/cryptography/cryptography-0.2.1-cp33-none-win32.whl#md5=81acca90caf8a45f2ca73f3f9859fae4 (from https://pypi.python.org/simple/cryptography/) because it is not compatible with this Python
    Found link https://pypi.python.org/packages/source/c/cryptography/cryptography-0.1.tar.gz#md5=bdc1c5fe069deca7467b71a0cc538f17 (from https://pypi.python.org/simple/cryptography/), version: 0.1
    Found link https://pypi.python.org/packages/source/c/cryptography/cryptography-0.2.1.tar.gz#md5=872fc04268dadc66a0305ae5ab1c123b (from https://pypi.python.org/simple/cryptography/), version: 0.2.1
    Found link https://pypi.python.org/packages/source/c/cryptography/cryptography-0.2.tar.gz#md5=8a3d21e837a21e1b7634ee1f22b06bb6 (from https://pypi.python.org/simple/cryptography/), version: 0.2
  Using version 0.2.1 (newest of versions: 0.2.1, 0.2, 0.1)
  Downloading from URL https://pypi.python.org/packages/source/c/cryptography/cryptography-0.2.1.tar.gz#md5=872fc04268dadc66a0305ae5ab1c123b (from https://pypi.python.org/simple/cryptography/)
  Running setup.py (path:c:\users\paco\appdata\local\temp\pip_build_Paco\cryptography\setup.py) egg_info for package cryptography
    In file included from c/_cffi_backend.c:7:0:
    c/misc_win32.h:225:23: error: two or more data types in declaration specifiers
    c/misc_win32.h:225:1: warning: useless type name in empty declaration [enabled by default]
    c/_cffi_backend.c: In function 'convert_array_from_object':
    c/_cffi_backend.c:1105:26: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:1105:26: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c:1130:30: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:1130:30: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c:1150:30: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:1150:30: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c: In function 'convert_struct_from_object':
    c/_cffi_backend.c:1183:26: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:1183:26: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c:1196:30: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:1196:30: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c: In function 'cdata_repr':
    c/_cffi_backend.c:1583:13: warning: unknown conversion type character 'L' in format [-Wformat]
    c/_cffi_backend.c:1583:13: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c:1595:9: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:1595:9: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c: In function 'cdataowning_repr':
    c/_cffi_backend.c:1647:30: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:1647:30: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c: In function '_cdata_get_indexed_ptr':
    c/_cffi_backend.c:1820:26: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:1820:26: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:1820:26: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c: In function '_cdata_getslicearg':
    c/_cffi_backend.c:1872:26: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:1872:26: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:1872:26: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c: In function 'cdata_ass_slice':
    c/_cffi_backend.c:1951:26: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:1951:26: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:1951:26: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c:1969:30: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:1969:30: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:1969:30: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c:1983:22: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:1983:22: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c: In function 'cdata_call':
    c/_cffi_backend.c:2367:30: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:2367:30: warning: format '%s' expects argument of type 'char *', but argument 3 has type 'Py_ssize_t' [-Wformat]
    c/_cffi_backend.c:2367:30: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c: In function 'cast_to_integer_or_char':
    c/_cffi_backend.c:2916:26: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:2916:26: warning: format '%s' expects argument of type 'char *', but argument 3 has type 'Py_ssize_t' [-Wformat]
    c/_cffi_backend.c:2916:26: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c:2928:26: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:2928:26: warning: format '%s' expects argument of type 'char *', but argument 3 has type 'Py_ssize_t' [-Wformat]
    c/_cffi_backend.c:2928:26: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c: In function 'new_array_type':
    c/_cffi_backend.c:3480:9: warning: unknown conversion type character 'l' in format [-Wformat]
    c/_cffi_backend.c:3480:9: warning: too many arguments for format [-Wformat-extra-args]
    c/_cffi_backend.c: In function 'b_complete_struct_or_union':
    c/_cffi_backend.c:3878:22: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:3878:22: warning: unknown conversion type character 'z' in format [-Wformat]
    c/_cffi_backend.c:3878:22: warning: too many arguments for format [-Wformat-extra-args]
    Traceback (most recent call last):
      File "<string>", line 17, in <module>
      File "c:\users\paco\appdata\local\temp\pip_build_Paco\cryptography\setup.py", line 113, in <module>
        "build": cffi_build,
      File "D:\Anaconda\lib\distutils\core.py", line 112, in setup
        _setup_distribution = dist = klass(attrs)
      File "build\bdist.win-amd64\egg\setuptools\dist.py", line 239, in __init__
      File "build\bdist.win-amd64\egg\setuptools\dist.py", line 264, in fetch_build_eggs
      File "build\bdist.win-amd64\egg\pkg_resources.py", line 580, in resolve
        dist = best[req.key] = env.best_match(req, ws, installer)
      File "build\bdist.win-amd64\egg\pkg_resources.py", line 818, in best_match
        return self.obtain(req, installer) # try and download/install
      File "build\bdist.win-amd64\egg\pkg_resources.py", line 830, in obtain
        return installer(requirement)
      File "build\bdist.win-amd64\egg\setuptools\dist.py", line 314, in fetch_build_egg
      File "build\bdist.win-amd64\egg\setuptools\command\easy_install.py", line 593, in easy_install

      File "build\bdist.win-amd64\egg\setuptools\command\easy_install.py", line 623, in install_item

      File "build\bdist.win-amd64\egg\setuptools\command\easy_install.py", line 809, in install_eggs

      File "build\bdist.win-amd64\egg\setuptools\command\easy_install.py", line 1015, in build_and_install

      File "build\bdist.win-amd64\egg\setuptools\command\easy_install.py", line 1003, in run_setup

    distutils.errors.DistutilsError: Setup script exited with error: command 'gcc' failed with exit status 1
    Complete output from command python setup.py egg_info:
    In file included from c/_cffi_backend.c:7:0:

c/misc_win32.h:225:23: error: two or more data types in declaration specifiers

c/misc_win32.h:225:1: warning: useless type name in empty declaration [enabled by default]

c/_cffi_backend.c: In function 'convert_array_from_object':

c/_cffi_backend.c:1105:26: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:1105:26: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c:1130:30: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:1130:30: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c:1150:30: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:1150:30: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c: In function 'convert_struct_from_object':

c/_cffi_backend.c:1183:26: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:1183:26: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c:1196:30: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:1196:30: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c: In function 'cdata_repr':

c/_cffi_backend.c:1583:13: warning: unknown conversion type character 'L' in format [-Wformat]

c/_cffi_backend.c:1583:13: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c:1595:9: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:1595:9: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c: In function 'cdataowning_repr':

c/_cffi_backend.c:1647:30: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:1647:30: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c: In function '_cdata_get_indexed_ptr':

c/_cffi_backend.c:1820:26: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:1820:26: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:1820:26: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c: In function '_cdata_getslicearg':

c/_cffi_backend.c:1872:26: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:1872:26: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:1872:26: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c: In function 'cdata_ass_slice':

c/_cffi_backend.c:1951:26: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:1951:26: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:1951:26: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c:1969:30: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:1969:30: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:1969:30: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c:1983:22: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:1983:22: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c: In function 'cdata_call':

c/_cffi_backend.c:2367:30: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:2367:30: warning: format '%s' expects argument of type 'char *', but argument 3 has type 'Py_ssize_t' [-Wformat]

c/_cffi_backend.c:2367:30: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c: In function 'cast_to_integer_or_char':

c/_cffi_backend.c:2916:26: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:2916:26: warning: format '%s' expects argument of type 'char *', but argument 3 has type 'Py_ssize_t' [-Wformat]

c/_cffi_backend.c:2916:26: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c:2928:26: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:2928:26: warning: format '%s' expects argument of type 'char *', but argument 3 has type 'Py_ssize_t' [-Wformat]

c/_cffi_backend.c:2928:26: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c: In function 'new_array_type':

c/_cffi_backend.c:3480:9: warning: unknown conversion type character 'l' in format [-Wformat]

c/_cffi_backend.c:3480:9: warning: too many arguments for format [-Wformat-extra-args]

c/_cffi_backend.c: In function 'b_complete_struct_or_union':

c/_cffi_backend.c:3878:22: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:3878:22: warning: unknown conversion type character 'z' in format [-Wformat]

c/_cffi_backend.c:3878:22: warning: too many arguments for format [-Wformat-extra-args]

Traceback (most recent call last):

  File "<string>", line 17, in <module>

  File "c:\users\paco\appdata\local\temp\pip_build_Paco\cryptography\setup.py", line 113, in <module>

    "build": cffi_build,

  File "D:\Anaconda\lib\distutils\core.py", line 112, in setup

    _setup_distribution = dist = klass(attrs)

  File "build\bdist.win-amd64\egg\setuptools\dist.py", line 239, in __init__

  File "build\bdist.win-amd64\egg\setuptools\dist.py", line 264, in fetch_build_eggs

  File "build\bdist.win-amd64\egg\pkg_resources.py", line 580, in resolve

    dist = best[req.key] = env.best_match(req, ws, installer)

  File "build\bdist.win-amd64\egg\pkg_resources.py", line 818, in best_match

    return self.obtain(req, installer) # try and download/install

  File "build\bdist.win-amd64\egg\pkg_resources.py", line 830, in obtain

    return installer(requirement)

  File "build\bdist.win-amd64\egg\setuptools\dist.py", line 314, in fetch_build_egg

  File "build\bdist.win-amd64\egg\setuptools\command\easy_install.py", line 593, in easy_install



  File "build\bdist.win-amd64\egg\setuptools\command\easy_install.py", line 623, in install_item



  File "build\bdist.win-amd64\egg\setuptools\command\easy_install.py", line 809, in install_eggs



  File "build\bdist.win-amd64\egg\setuptools\command\easy_install.py", line 1015, in build_and_install



  File "build\bdist.win-amd64\egg\setuptools\command\easy_install.py", line 1003, in run_setup



distutils.errors.DistutilsError: Setup script exited with error: command 'gcc' failed with exit status 1

----------------------------------------
Cleaning up...
  Removing temporary dir c:\users\paco\appdata\local\temp\pip_build_Paco...
Command python setup.py egg_info failed with error code 1 in c:\users\paco\appdata\local\temp\pip_build_Paco\cryptography
Exception information:
Traceback (most recent call last):
  File "D:\Anaconda\lib\site-packages\pip-1.5.4-py2.7.egg\pip\basecommand.py", line 122, in main
    status = self.run(options, args)
  File "D:\Anaconda\lib\site-packages\pip-1.5.4-py2.7.egg\pip\commands\install.py", line 278, in run
    requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundle=self.bundle)
  File "D:\Anaconda\lib\site-packages\pip-1.5.4-py2.7.egg\pip\req.py", line 1229, in prepare_files
    req_to_install.run_egg_info()
  File "D:\Anaconda\lib\site-packages\pip-1.5.4-py2.7.egg\pip\req.py", line 325, in run_egg_info
    command_desc='python setup.py egg_info')
  File "D:\Anaconda\lib\site-packages\pip-1.5.4-py2.7.egg\pip\util.py", line 697, in call_subprocess
    % (command_desc, proc.returncode, cwd))
InstallationError: Command python setup.py egg_info failed with error code 1 in c:\users\paco\appdata\local\temp\pip_build_Paco\cryptography

I found other egg_info error posts (here and here) but the solutions there provided wouldn’t solve my problem. Also, I am able to install other packages through PIP.

PIP version 1.5.4 setuptools version 2.2

Question 2

I had a similar issue, and found I was simply missing a dependency (libssl-dev, for me). As referenced in https://cryptography.io/en/latest/installation/, ensure that all dependencies are met:

On Windows

If you’re on Windows you’ll need to make sure you have OpenSSL installed. There are pre-compiled binaries available. If your installation is in an unusual location set the LIB and INCLUDE environment variables to include the corresponding locations. For example:

C:\> \path\to\vcvarsall.bat x86_amd64
C:\> set LIB=C:\OpenSSL-1.0.1f-64bit\lib;%LIB%
C:\> set INCLUDE=C:\OpenSSL-1.0.1f-64bit\include;%INCLUDE%
C:\> pip install cryptography

Building cryptography on Linux

cryptography should build very easily on Linux provided you have a C compiler, headers for Python (if you’re not using pypy), and headers for the OpenSSL and libffi libraries available on your system.

For Debian and Ubuntu, the following command will ensure that the required dependencies are installed:

sudo apt-get install build-essential libssl-dev libffi-dev python-dev

For Fedora and RHEL-derivatives, the following command will ensure that the required dependencies are installed:

sudo yum install gcc libffi-devel python-devel OpenSSL-devel

You should now be able to build and install cryptography with the usual.

pip install cryptography

Question 3

This is a condensed version of the information found on cryptography’s installation docs page. Consult that page for the latest details.

Since this SO question keeps coming up I’ll drop a response here too (I am one of the pyca/cryptography developers). Here’s what you need to reliably install pyca/cryptography on the 3 major platforms.

Please note in all these cases it is highly recommended that you install into a virtualenv and not into the global package space. This is not specific to cryptography but rather is generic advice to keep your Python installation reliable. The global package space in OS provided Pythons is owned by the system and installing things via pip into it is asking for trouble.

Windows

Upgrade to the latest pip (8.1.2 as of June 2016) and just pip install cryptography

cryptography and cffi are both shipped as statically linked wheels.

OS X

Upgrade to the latest pip (8.1.2 as of June 2016) and just pip install cryptography

cryptography and cffi are both shipped as statically linked wheels. This will work for pyenv Python, system Python, homebrew Python, etc. As long as you’re on the latest pip you won’t even need a compiler.

Linux

As of version 2.0 cryptography ships manylinux wheels. This means users with pip 8.1+ running on a glibc-based distribution (almost everything except Alpine Linux) and on x86/x86-64 no longer need a compiler or headers because you’ll get a precompiled wheel automatically. With version 3.1 we now also ship aarch64 wheels (which require a very recent pip…20.0+). So, first thing you should try is upgrading your pip!

If you aren’t manylinux compatible then here’s what you need to do:

You’ll need a C compiler, libffi + its development headers, and openssl + its development headers.

Debian or Ubuntu derived distributions

apt-get install build-essential libssl-dev libffi-dev python-dev followed by

pip install cryptography

Red Hat derived distributions

yum install gcc openssl-devel libffi-devel python-devel followed by

pip install cryptography

Question 4

For those of you running OS X, here is what worked for me:

brew install openssl
env ARCHFLAGS="-arch x86_64" LDFLAGS="-L/usr/local/opt/openssl/lib" CFLAGS="-I/usr/local/opt/openssl/include"
pip install cryptography

(Running 10.9 Mavericks)

You may also want to try merging the flags and pip commands to the following per the comment below:

brew install openssl
env ARCHFLAGS="-arch x86_64" LDFLAGS="-L/usr/local/opt/openssl/lib" CFLAGS="-I/usr/local/opt/openssl/include" pip install cryptography

Question 5

This worked for me in El Capitan

brew install pkg-config libffi openssl
env LDFLAGS="-L$(brew --prefix openssl)/lib" CFLAGS="-I$(brew --prefix openssl)/include" pip install cryptography

You can also check the thread here : https://github.com/pyca/cryptography/issues/2350

Question 6

This solved the problem for me (Ubuntu 16.04):

sudo apt-get install build-essential libssl-dev libffi-dev python-dev python3-dev

and then it was working like this:

pip install cryptography
pip install pyopenssl ndg-httpsclient pyasn1

Question 7

Apparently on recent versions of OSX this may be caused by Apple shipping their own version of OpenSSL, which doesn’t work with the cryptography library.

Recent versions of the cryptography library ship with their own native dependencies, but to get them you’ll need to upgrade pip, and possibly also virtual env. So for me, the solution was:

pip install --upgrade --force-reinstall pip virtualenv

Question 8

How I solved “Failed cleaning build dir for cryptography”
(I came here from google to result for this error.)

note: using a virtualenv

TL;DR:

my file /etc/apt/sources.list wasn’t correctly configured for my debian 8.

Explanations:

I wanted to install paramiko. paramiko needs cryptography.

I got these errors: first with pip install cryptography:

(...)
  ----------------------------------------
  Failed cleaning build dir for cryptography
Failed to build cryptography
(...)
    ----------------------------------------
Command "/home/myuser/pyenvs/testo/bin/python -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-HXWKAO/cryptography/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-WjqY6V-record/install-record.txt --single-version-externally-managed --compile --install-headers /home/myuser/pyenvs/testo/include/site/python2.7/cryptography" failed with error code 1 in /tmp/pip-build-HXWKAO/cryptography/

and then with sudo apt-get install build-essential :

Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 build-essential : Depends: libc6-dev but it is not going to be installed > or
                            libc-dev
                   Depends: gcc (>= 4:4.4.3) but it is not going to be installed
                   Depends: g++ (>= 4:4.4.3) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

(Not exactly the same errors as OP but I’m here to help eventually)

Solving:

After testing almost every command from every posts I end up going on
https://wiki.debian.org/SourcesList
and copy pasted my adequate config in the file /etc/apt/sources.list

then:

sudo aptitude update

and then

sudo apt-get install build-essential libssl-dev libffi-dev python-dev

and then

pip install cryptography

hth

Question 9

I tried many solutions above, but only after the installation of the following lib I could install cryptography:

sudo apt install libssl1.0

I’m using Ubuntu 18.04, but it will work on Ubuntu 18.10 as well.

UPD: To solve this error on Ubuntu 20 I had to replace cryptography==1.9 with cryptography==2.1.1

Question 10

This worked for me (I’m using Ubuntu 14.04):

first install libffi-dev libssl-dev libpython2.7-dev:

sudo apt-get install libffi-dev libssl-dev libpython2.7-dev

then inside virtualenv:

pip install cryptography
pip install pyopenssl ndg-httpsclient pyasn1

Sources:

https://stackoverflow.com/a/32800685/5123544

https://stackoverflow.com/a/29202163/5123544

Question 11

Nick Woodham’s answer didn’t work on OSX 10.11 El Capitan for me, but this did.

brew install openssl
CFLAGS="-I/usr/local/opt/openssl/include" pip install cryptography==0.8

Question 12

If you are using python3, you need to install python3-dev. This fixed my problem sudo apt-get install python3-dev.

Question 13

I was having issues with installing cryptography==1.7.1 on Ubuntu 16.04 and none of the answers above helped. So, I upgraded the requirement to a compatible 1.8.2 and the setup was successful. Note that you would still need build essentials & other dependencies mentioned in the top (most upvoted) answer.

Question 14

I was having a problem running sudo pip install cryptography because it would not find ffi when trying to compile. (OSX – Yosemite)

I solved it by downloading libffi and setting up the env var.

$ brew install pkg-config libffi
$ export PKG_CONFIG_PATH=/usr/local/Cellar/libffi/3.0.13/lib/pkgconfig/
$ pip install cryptography

Question 15

This works on El Capitan with MacPorts:

$ sudo port install openssl
$ env LDFLAGS="-L/opt/local/lib" CFLAGS="-I/opt/local/include" pip install cryptography

Question 16

If you are building a python package distribution in a .gitlab-ci.yml file in for GitLab CI that uses a gitlab runner deployed in an AWS EC2 machine

 - apk add --update alpine-sdk && \
 - apk add libffi-dev openssl-dev && \
 - apk --no-cache --update add build-base

Question 17

I noticed the original poster was clearly using a windows installation… and the best answers above are all for other OSs… so here goes. This assumes you have installed Python 2.7 which is the most widely supported (though old) version.

Install the “Visual C++ Compiler for Python“
Open an Administrative command prompt window

Re-run pip install (package) e.g.

cd C:\Python27\Scripts
pip install cryptography  (or pycrypto, fabric, etc)

Question 18

I encountered a similar issue recently. In my case the versions of cffi and cryptography written in requirements.txt weren’t compatible (cffi==1.8.9 and cryptography==1.9). I solved updating cffi with the last available version.

Question 19

I actually ran into this same prob trying to install Scrapy which depends on cryptography being installed first. I’m on Win764-bit with Python 2.7 64-bit installed. @jsonm’s answer eventually worked for me, but first I had to Copy C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\bin\vcvarsx86_amd64.bat to the x86_amd64 subdir within that bin dir so the vcvarsall.bat would stop throwing an error saying it was missing the config. If you need to configure env vars for a different setup, be sure to copy to corresponding vcvars bat file to the corresponding subdir or the first command below might not work.

Then I ran the following from a commandline as per @jsonm’s instructions (tweaked for my config)…

C:\> "C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\vcvarsall.bat" x86_amd64 
C:\> set LIB=C:\OpenSSL-Win64\lib;%LIB% 
C:\> set INCLUDE=C:\OpenSSL-Win64\include;%INCLUDE% 
C:\> pip install cryptography

And it worked.

Question 20

I had this error too. After continuing to get this error even after installing openSSL, I eventually tried installing from wheel files from https://pypi.python.org/pypi/cryptography/0.2.2#downloads. It worked!

Question 21

i downloaded paramiko full source code from pypi and did

python setup.py install

it worked flawlessly

all default pythondev / openssl /libffi packages are already present in rhel.

downloading rpms have rpm mismatch and more trouble

Question 22

I am having same problem:

pip install cryptography

.
.
.
Installing collected packages: cffi, cryptography
     Running setup.py install for cffi ... error

Then I install libffi-devel and problem is solved

yum install libffi-devel

Question 23

Those two commands fixed it for me:

brew install openssl
brew link openssl --force

Source: https://github.com/phusion/passenger/issues/1630#issuecomment-147527656

Question 24

I resolved this by upgrading from cryptography 1.9 to 2.4.2

Python 实用宝典

无法使用PIP和setup.py安装Python密码术软件包

问题：无法使用PIP和setup.py安装Python密码术软件包

回答 0

在Windows上

在Linux上构建加密

On Windows

Building cryptography on Linux

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TL; DR：

说明：

解决方法：

TL;DR:

Explanations:

Solving:

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