Compiling Python via Pyenv on Archlinux but missing OpenSSL

I am trying to install python via pyenv on my new ArchLinux install

pyenv install 3.5.1Downloading Python-3.5.1.tar.xz...
-> https://www.python.org/ftp/python/3.5.1/Python-3.5.1.tar.xz
Installing Python-3.5.1...
ERROR: The Python ssl extension was not compiled. Missing the OpenSSL lib?

Please consult to the Wiki page to fix the problem.
https://github.com/pyenv/pyenv/wiki/Common-build-problems


BUILD FAILED (Arch Linux using python-build 20160602)

Inspect or clean up the working tree at /tmp/python-build.20170515113212.3725
Results logged to /tmp/python-build.20170515113212.3725.log

Last 10 log lines:
(cd /home/maximilian/.pyenv/versions/3.5.1/share/man/man1; ln -s python3.5.1 python3.1)
if test "xupgrade" != "xno"  ; then \
    case upgrade in \
        upgrade) ensurepip="--upgrade" ;; \
        install|*) ensurepip="" ;; \
    esac; \
     ./python -E -m ensurepip \
        $ensurepip --root=/ ; \
fi
Ignoring ensurepip failure: pip 7.1.2 requires SSL/TLS

And it failes due to missing OpenSSL support. I had it running on my previous Arch installation but I can't remember what I did back then.

The FAQ in the Wiki does not provide a working solution

Solution

Please try it.:

CFLAGS=-I/usr/include/openssl-1.0 \
LDFLAGS=-L/usr/lib64/openssl-1.0 \
pyenv install -v 3.5.1

ArchLinux packages:

$ pacman -Q | grep openssl
openssl 1.1.0.e-1
openssl-1.0 1.0.2.k-3
python-pyopenssl 17.0.0-1
python2-pyopenssl 17.0.0-1