Pip Install Twisted Error 1

Question

When using pip install Twisted in virtualenv on Mac osx 10.9.4, I get this result:

Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/9r/3b500gbs3093ms87mqqbckr80000gn/T/pip-build-doynftp7/twisted/

I am not sure how to resolve. I used easy_install, but I get a SSL verification issue. Anyone have similar issue? The rest of error message is below.

 Collecting twisted  Using cached Twisted-16.6.0.tar.bz2  Complete output from command python setup.py egg_info: Download error on https://pypi.python.org/simple/incremental/: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:749) -- Some packages may not be found! Couldn't find index page for 'incremental' (maybe misspelled?) Download error on https://pypi.python.org/simple/: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:749) -- Some packages may not be found! No local packages or working download links found for incremental>=16.10.1 Traceback (most recent call last):   File "<string>", line 1, in <module>   File "/private/var/folders/9r/3b500gbs3093ms87mqqbckr80000gn/T/pip-build-lqvxc68n/twisted/setup.py", line 21, in <module>     setuptools.setup(**_setup["getSetupArgs"]())   File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/distutils/core.py", line 108, in setup     _setup_distribution = dist = klass(attrs)   File "/Users/Complex-Cauchy/1/lib/python3.6/site-packages/setuptools/dist.py", line 317, in __init__     self.fetch_build_eggs(attrs['setup_requires'])   File "/Users/Complex-Cauchy/1/lib/python3.6/site-packages/setuptools/dist.py", line 372, in fetch_build_eggs     replace_conflicting=True,   File "/Users/Complex-Cauchy/1/lib/python3.6/site-packages/pkg_resources/__init__.py", line 851, in resolve     dist = best[req.key] = env.best_match(req, ws, installer)   File "/Users/Complex-Cauchy/1/lib/python3.6/site-packages/pkg_resources/__init__.py", line 1123, in best_match     return self.obtain(req, installer)   File "/Users/Complex-Cauchy/1/lib/python3.6/site-packages/pkg_resources/__init__.py", line 1135, in obtain     return installer(requirement)   File "/Users/Complex-Cauchy/1/lib/python3.6/site-packages/setuptools/dist.py", line 440, in fetch_build_egg     return cmd.easy_install(req)   File "/Users/Complex-Cauchy/1/lib/python3.6/site-packages/setuptools/command/easy_install.py", line 668, in easy_install     raise DistutilsError(msg) distutils.errors.DistutilsError: Could not find suitable distribution for Requirement.parse('incremental>=16.10.1')  ---------------------------------------- 

Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/9r/3b500gbs3093ms87mqqbckr80000gn/T/pip-build-lqvxc68n/twisted/

Running openssl s_client -showcerts -connect pypi.python.org:443 returns the following:

 CONNECTED(00000003)  depth=1 /C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 Extended     Validation Server CA  verify error:num=20:unable to get local issuer certificate  verify return:0  ---  Certificate chain   0 s:/businessCategory=Private Organization/1.3.6.1.4.1.311.60.2.1.3=US/1.3.6.1.4.1.311.60.2.1.2=Delaware/serialNumber=3359300/street=16 Allen    Rd/postalCode=03894-4801/C=US/ST=NH/L=Wolfeboro/O=Python Software Foundation/CN=www.python.org   i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 Extended Validation Server CA   -----BEGIN CERTIFICATE-----   MIIIWjCCB0KgAwIBAgIQCXCW7BLw16II/CMOsOFe/jANBgkqhkiG9w0BAQsFADB1   ..  -----END CERTIFICATE-----  1 s:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 Extended Validation Server CA  i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance EV Root CA  -----BEGIN CERTIFICATE----- MIIEtjCCA56gAwIBAgIQDHmpRLCMEZUgkmFf4msdgzANBgkqhkiG9w0BAQsFADBs .... -----END CERTIFICATE-----  Server certificate  subject=/businessCategory=Private Organization/1.3.6.1.4.1.311.60.2.1.3=US/1.3.6.1.4.1.311.60.2.1.2=Delaware/serialNumber=3359300/street=16 Allen Rd/postalCode=03894-4801/C=US/ST=NH/L=Wolfeboro/O=Python Software Foundation/CN=www.python.org issuer=/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 Extended  Validation Server CA --- No client certificate CA names sent --- SSL handshake has read 3524 bytes and written 456 bytes --- New, TLSv1/SSLv3, Cipher is AES128-SHA Server public key is 2048 bit Secure Renegotiation IS supported Compression: NONE Expansion: NONE SSL-Session: Protocol  : TLSv1 Cipher    : AES128-SHA Session-ID: BC7695FF86D2B82B20468A13E3F3E13AE23776B500E64665305EEBAF49BB54D1 Session-ID-ctx:  Master-Key:8D25B34237A3C74E90317D87BA74A2AAF0E8C424FB2ADE3D72E5F234D5E043C4527641290B928B3A22 1BE7D44116CFB1 Key-Arg   : None Start Time: 1487035770 Timeout   : 300 (sec) Verify return code: 0 (ok) 

Answer 1

I had the same issue on a Mac OSX 10.11.6 in a new virtualenv with a fresh install of Python3.6.1. In my case, I had old versions of the Twisted dependency incremental installed, which prevented the installation.

pip install --upgrade incremental pip install Twisted 

Note I: I was installing a whole array of packages from a requirements file where the same incremental version was specified. I really wonder why the upgrade of incremental helped and have no clue what actually went wrong. If someone can clarify, that would be great.

Note II: Installing incremental ahead of of Twisted seems to be necessary on fresh installs, too [Experienced when working with CentOS7].

Note III: The issue was communicated to the amazing Twisted community and once Twisted ticket #9457 is implemented and in the release this question and my answer should become obsolete.

Answer 2

The error you reported is incomplete. There are almost certainly more details above it in the pip output. It would help if edit them into your question.

A survey of similar questions:

• Python pip install gives "Command "python setup.py egg_info" failed with error code 1"
• Can't install via pip because of egg_info error
• Python pip install fails: invalid command egg_info
• https://github.com/donnemartin/gitsome/issues/4

Suggests that:

• You're missing setuptools. Inside a virtualenv (you did activate your virtualenv, right?) this seems implausible.
• You're missing part of the C toolchain - a compiler, some necessary headers, etc. Twisted includes C extensions so this seems possible. Do you have a C toolchain?
• You're using an incompatible version of Python. What version of Python are you using?

But the additional certificate verification failure errors you've included suggest it's not caused by any of these. Instead, a dependency cannot be downloaded because pip can't do a TLS handshake with the PyPI server it needs to download the dependency from.

This could be caused by many different things. Can your system's browsers load https://pypi.python.org/? If not, perhaps there's something wrong system-wide: you might have outdated certificate authority certificates or there might be a man-in-the-middle attack taking place.

openssl s_client can sometimes be useful for debugging issues like these. Try:

openssl s_client -showcerts -connect pypi.python.org:443 

This may give you more details about what's happening at the TLS layer. If openssl s_client also has trouble verifying the certificate, you know there's something wrong system-wide. If not, we can narrow it down to a pip or Python problem.