_default_ VirtualHost overlap on port 80, the first has precedence

% sudo /opt/local/apache2/bin/apachectl -k restart

[warn] default VirtualHost overlap on port 80, the first has precedence

!?

<VirtualHost *:80>
    ServerName mng.local
    DocumentRoot /Users/test/Sites/apps/web_user/public_html
    <Directory "/Users/test/Sites/apps/web_user/public_html">
        AllowOverride All
        Order deny,allow
        Allow from all
    </Directory>
</VirtualHost>

これに、NameVirtualHost *:80を足します。

NameVirtualHost *:80
<VirtualHost *:80>
    ServerName mng.local
    DocumentRoot /Users/test/Sites/apps/web_user/public_html
    <Directory "/Users/test/Sites/apps/web_user/public_html">
        AllowOverride All
        Order deny,allow
        Allow from all
    </Directory>
</VirtualHost>

これで動くようになりました。