psycopg2 installation error - Library not loaded: libssl.dylib

Does the error say libssl.dylib version is too old?

On my mac, the error is that libssl.dylib and libcrypto.dylib is too old for pyscopg to use. The openssl package used by mac is 0.98, while pyscopg needs 1.0.0 or later version.

My solution is this:

1. install openssl from brew

   $ brew install openssl
   

2. copy libssl.1.0.0.dylib and libcrypto.1.0.0.dylib from /usr/local/Cellar/openssl/1.0.1c to /usr/lib/

   $ cd /usr/local/Cellar/openssl/1.0.1c/lib
   $ sudo cp libssl.1.0.0.dylib libcrypto.1.0.0.dylib /usr/lib/
   

3. in /usr/lib directory, make a softlink libssl.dylib and libcrypto.dylib. You may have to remove the existing links.

   $ sudo rm libssl.dylib libcrypto.dylib
   $ sudo ln -s libssl.1.0.0.dylib libssl.dylib
   $ sudo ln -s libcrypto.1.0.0.dylib libcrypto.dylib
   

I think in Mac we need:

export LDFLAGS="-L/usr/local/opt/openssl/lib"

On OSX 10.11+ (El Capitan or later) solution with replacing symlinks (see above - https://stackoverflow.com/a/11911870/565525) sudo rm libssl.dylib libcrypto.dylib reports Operation not permitted. Solution that worked for me was:

brew install openssl

Find where openssl brew libs are located, start searching from directory /usr/local/Cellar/openssl. In my case it is in /usr/local/Cellar/openssl/1.0.2d_1/lib

Finally set up DYLD_LIBRARY_PATH, i.e. add a line like this into .bash_profile :

# replace location of lib files with folder name you found in previous step
export DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH:/usr/local/Cellar/openssl/1.0.2d_1/lib

restart shell, or just source ~/.bash_profile and test if it works:

$ python -c"import psycopg2  ;   print('psycopg2 is now ok')"