Trouble installing m2crypto with pip on OS X / macOS

thanks to therealmarv env flags i was able to get this to work with the macports version of openssl/swig, this is what i did:

sudo port install openssl
sudo port install swig
sudo port install swig-python

then use therealmarv lines but replace "$(brew --prefix openssl)" with the dir from macports which should be "/opt/local"

sudo env LDFLAGS="-L/opt/local/lib" \
CFLAGS="-I/opt/local/include" \
SWIG_FEATURES="-cpperraswarn -includeall -I/opt/local/include" \
pip install M2Crypto

I wanted a nicer way without installing manually and using only Homebrew (which also does not link openssl by default). Also using pip was a requirement. This seems to work with newest m2crypto 0.22.5. I also tested it once with m2crypto 0.22.3 and seems also to work. The OpenSSL version here is 1.0.2d:

brew install openssl
brew install swig

Finally install m2crypto on macOS in your Bash. It is a long command but it changes SWIG and clang environment variables only during pip install so that m2crypto will get all OpenSSL requirements:

env LDFLAGS="-L$(brew --prefix openssl)/lib" \
CFLAGS="-I$(brew --prefix openssl)/include" \
SWIG_FEATURES="-cpperraswarn -includeall -I$(brew --prefix openssl)/include" \
pip install m2crypto

btw. the last command also works if you use e.g. a requirements.txt.

Update:
Additional also the command for fish shell users...

env LDFLAGS="-L"(brew --prefix openssl)"/lib" \
CFLAGS="-I"(brew --prefix openssl)"/include" \
SWIG_FEATURES="-cpperraswarn -includeall -I"(brew --prefix openssl)"/include" \
pip install m2crypto