io_stream.lo Error 1 when installing php extension

Question

I'm trying to install mongo php extension on OSX 10.11 but the command:

sudo pecl install mongo

gives the following error:

...
In file included from /private/tmp/pear/install/mongo/io_stream.c:34:
/private/tmp/pear/install/mongo/contrib/php-ssl.h:33:10: fatal error: 'openssl/evp.h' file not found
#include <openssl/evp.h>
         ^
1 error generated.
make: *** [io_stream.lo] Error 1
ERROR: `make' failed

Answer 1

1. brew install openssl
2. ln -s /usr/local/Cellar/openssl/1.0.2d_1/include/openssl /usr/local/include/openssl