PycURL error: ConfigurationError: Curl is configured to use SSL, but we have not been able to determine which SSL backend it is using. Please see PycURL documentation for how to specify the SSL backend manually.

HowToFixPycURLErrorMacOS.md

Partly pulled from the comments here: pycurl/pycurl#526

May also be a fix for this error:

ImportError: pycurl: libcurl link-time ssl backend (none/other) is different from compile-time ssl backend (openssl)

If you try to install PycURL and receive this error:

 Curl is configured to use SSL, but we have not been able to determine which SSL backend it is using

Here's one way to fix. First, the pre-requisites:

• Install Xcode command line tools with xcode-select --install if they aren't already.
• Install Homebrew if you don't have it already: https://brew.sh/
• Uninstall your current version of cURL if you have one installed.
• Uninstall your current version of PycURL.

Then do the following:

1. Use brew install curl --with-openssl to install cURL
2. Run export PYCURL_SSL_LIBRARY=openssl to set the library for PycURL
3. Run the following commmand (really 3 commands in 1) to tell the compiler where to find openssl, then download and compile pycurl with pip.

export LDFLAGS=-L/usr/local/opt/openssl/lib;export CPPFLAGS=-I/usr/local/opt/openssl/include; pip install pycurl --compile --no-cache-dir

@Allen-Liang Did you figure it out? I have the same issue using Python2, it is working in Python3.
It worked to me until yesterday when I execute brew upgrade and all my libs (curl & openssl) have been updated.