libphp5.so requires version 12.0.0 or later, but libxml2.2.dylib provides version 10.0.0

➜  apache2   apachectl -M

httpd: Syntax error on line 178 of /private/etc/apache2/httpd.conf: Cannot load /usr/local/Cellar/php56/5.6.25_1/libexec/apache2/libphp5.so into server: dlopen(/usr/local/Cellar/php56/5.6.25_1/libexec/apache2/libphp5.so, 10): Library not loaded: /usr/local/opt/libxml2/lib/libxml2.2.dylib\n  Referenced from: /usr/local/Cellar/php56/5.6.25_1/libexec/apache2/libphp5.so\n  Reason: Incompatible library version: libphp5.so requires version 12.0.0 or later, but libxml2.2.dylib provides version 10.0.0

环境：MacOs 10.12
看报错信息，是类库版本不对，我尝试
brew install libxml2
brew link libxml2--force，然并卵啊
什么问题呢？