library not found for -lssl


I had this same issue. It was related to the Home Brew OpenSSL library being updated but the Mongo libraries not being updated to accommodate. Sadly, the Mongo .pc files include paths which have the OpenSSL version number in them, making them fragile when they get updated.
I needed to update the following file:
/usr/local/lib/pkgconfig/libmongoc-1.0.pc
and change the 'Libs' path such that it references the proper OpenSSL path:
-L/usr/local/Cellar/openssl/1.0.2h_1/lib
If I remember correctly, the old path had 1.0.2g in it.
Sadly, when we install openssl use brew command, the old version of openssl was not provided. You know why? @kjessup