Root ignored for "location = /"?

[Mark James]

Hello,

I want the index.html file in a particular directory to only be served when the domain's root URI is requested.

Using the config

server example.com;
index index.html;
location = / {
   root path/to/dir;
}

a request to example.com results in index.html in the Nginx default root "/html" directory being served.

The same thing happens with a trailing slash on the root, or when I substitute a trailing-slash alias directive.

If I use an alias directive without a trailing slash I get 403 error

    directory index of "path/to/dir" is forbidden.

There are no problems if I instead use "location /".

Can anyone suggest a reason or a resolution?

Thanks.

Mark