'bin/pip install cryptography' in a virtualenv fails unless libssl-dev is installed

[daira]

$ bin/pip install cryptography
[...]
    building '_Cryptography_cffi_4ed9e37dx4000d087' extension
    x86_64-linux-gnu-gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I/usr/include/python2.7 -c cryptography/hazmat/bindings/__pycache__/_Cryptography_cffi_4ed9e37dx4000d087.c -o /home/davidsarah/test-venv/build/cryptography/cryptography/hazmat/bindings/__pycache__/cryptography/hazmat/bindings/__pycache__/_Cryptography_cffi_4ed9e37dx4000d087.o
    cryptography/hazmat/bindings/__pycache__/_Cryptography_cffi_4ed9e37dx4000d087.c:194:25: fatal error: openssl/aes.h: No such file or directory
    compilation terminated.
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/home/davidsarah/test-venv/build/cryptography/setup.py", line 338, in <module>
        **keywords_with_side_effects(sys.argv)
      File "/usr/lib/python2.7/distutils/core.py", line 152, in setup
        dist.run_commands()
      File "/usr/lib/python2.7/distutils/dist.py", line 953, in run_commands
        self.run_command(cmd)
      File "/usr/lib/python2.7/distutils/dist.py", line 971, in run_command
        cmd_obj.ensure_finalized()
      File "/usr/lib/python2.7/distutils/cmd.py", line 109, in ensure_finalized
        self.finalize_options()
      File "/home/davidsarah/test-venv/build/cryptography/setup.py", line 118, in finalize_options
        self.distribution.ext_modules = get_ext_modules()
      File "/home/davidsarah/test-venv/build/cryptography/setup.py", line 86, in get_ext_modules
        OpenSSLBinding().ffi.verifier.get_extension(),
      File "cryptography/hazmat/bindings/openssl/binding.py", line 89, in __init__
        self._ensure_ffi_initialized()
      File "cryptography/hazmat/bindings/openssl/binding.py", line 113, in _ensure_ffi_initialized
        libraries=libraries,
      File "cryptography/hazmat/bindings/utils.py", line 80, in build_ffi
        extra_link_args=extra_link_args,
      File "/home/davidsarah/test-venv/build/cryptography/cffi-0.8.6-py2.7-linux-x86_64.egg/cffi/api.py", line 340, in verify
        lib = self.verifier.load_library()
      File "/home/davidsarah/test-venv/build/cryptography/cffi-0.8.6-py2.7-linux-x86_64.egg/cffi/verifier.py", line 74, in load_library
        self._compile_module()
      File "/home/davidsarah/test-venv/build/cryptography/cffi-0.8.6-py2.7-linux-x86_64.egg/cffi/verifier.py", line 139, in _compile_module
        outputfilename = ffiplatform.compile(tmpdir, self.get_extension())
      File "/home/davidsarah/test-venv/build/cryptography/cffi-0.8.6-py2.7-linux-x86_64.egg/cffi/ffiplatform.py", line 25, in compile
        outputfilename = _build(tmpdir, ext)
      File "/home/davidsarah/test-venv/build/cryptography/cffi-0.8.6-py2.7-linux-x86_64.egg/cffi/ffiplatform.py", line 51, in _build
        raise VerificationError('%s: %s' % (e.__class__.__name__, e))
    cffi.ffiplatform.VerificationError: CompileError: command 'x86_64-linux-gnu-gcc' failed with exit status 1

Works after sudo apt-get install libssl-dev.

[warner]

Yup, this is true, unless you're on a platform that has binary wheels available (pyca provides them for mac, win32, win64). We've documented the need for libssl-dev on linux in docs/INSTALL.rst. So I think we can close this as a WONTFIX.