SSL backend error when using OpenSSL

Question

I was trying to install pycurl in a virtualenv using pip and I got this error

ImportError: pycurl: libcurl link-time ssl backend (openssl) is different from         


        

Answer 1

Not sure if this is because of running in a virtualenv, but on CentOS 7 these solutions weren't working for me; the compiled objects were still being grabbed from the cache dir when I was reinstalling. If you're running into the same problem after trying other solutions here, try the following:

pip uninstall pycurl
export PYCURL_SSL_LIBRARY=[nss|openssl|ssl|gnutls]
pip install pycurl --no-cache-dir

Answer 2

After being stuck on this for a long time, I found out that apple stopped including OpenSSL headers since OS X 10.11 El Capitan. how to fix?

1) brew install openssl

2) echo 'export PATH="/usr/local/opt/openssl/bin:$PATH"' >> ~/.bash_profile (or .zshrc for zsh, etc)

3) pip uninstall pycurl

4) pip install --install-option="--with-openssl" --install-option="--openssl-dir=/usr/local/opt/openssl" pycurl

Answer 3

This link sums up the reason why the errors occur and gives a clear instruction to fix the problem.

https://cscheng.info/2018/01/26/installing-pycurl-on-macos-high-sierra.html

For me, the problem occurred when I upgraded to High-Sierra from El Captain.

Answer 4

I'm on CentOS 7. I tried all of the above and couldn't get anything to work. It turns out I needed to run these as a root user. So if you're having trouble, try any of the above solutions as a root user. As an example, here is what worked for me:

su -
pip uninstall pycurl
export PYCURL_SSL_LIBRARY=[nss|openssl|ssl|gnutls]
pip install pycurl

Of course, all the usual disclaimers about running as a root user apply.

Note: [nss|openssl|ssl|gnutls] in the code above means to pick one, and don't include the square brackets or pipes. The person who asked the original question would have chosen openssl. In my particular case, I chose nss. Your error message should tell you which choice to make.

2019 Edit: Doing a sudo pip install might cause a problem with the machine's system install of Python. Perhaps try working in a Python virtual environment and install the packages there. If that doesn't work, the sudo trick in my answer is probably one of the last options to consider.

Answer 5

I encountered this problem and Sanket Jagtap's answer worked for me. I tried the answer with the most votes answer but it did not work.

My openssl old version is 1.0.1t, I think reinstalling openssl may solve this problem.

--- pycurl's openssl backend time....

I rebuilt the latest openssl and tried this answer. Check this out.

pip install --compile --install-option="--with-openssl" pycurl

This worked for me.

i recommend we should reinstall our openssl for try..

Answer 6

Same problem on amazonlinux - solved
I had this problem while creating a docker image based on amazonlinux, installing python3.7 and adding the pycurl module. All other python modules were installed correctly except pycurl. After trying many of the solutions proposed in the threads linked to this problem I finally solved my problem by using following commands for installation of all the pieces.
yum -y install python3 python3-devel gcc libcurl-devel aws-cli openssl-static.x86_64
then installed other modules like psycopg2-binary, requests, certifi using:
pip3 install --user --no-cache-dir -r requirements.txt

and finally installed pycurl module using:

pip3 install --user --global-option="--with-openssl" --no-cache-dir pycurl
and passing here the openssl global option. The installation of the static library openssl-static.x86_64 solved the problem in my case as using global option used by the second pip3 command.