When I tried to install PHP-7.0.1, i got the following warning at step 3:
configure: WARNING: unrecognized options: --with-mysql
and other installation guide may have similar issues —— doing a configure with MySQL support (ext/mysql) in PHP 7. The extension was deprecated in the recent version
//wiki.php.net/rfc/remove_deprecated_functionality_in_php7
then you could use ext/mysqli or ext/pdo_mysql instead, for example, configure PHP 7.x with:
./configure --enable-fpm --with-mysqli