Ability to set BaseURL on call to next()

[rgbkrk]

I'd like to be able to host a next.js app on it's own base path (e.g. /some/base/path/ - on a configurable http proxy). This is primarily for use with JupyterHub to run as a separate service (on e.g. /services/nextApp). I've gotten everything to work for the express app (that uses next handlers underneath) as well as the frontend's handling of the paths (the req.params -> query -> page/component are awesome with next.js).

The only issue I'm running into is that _next is assumed to be at the absolute path of /_next when it needs to be able to be served at /some/base/path/_next.

const app = next({ dev, baseURL: '/asdf' });

• I have searched the issues of this repository and believe that this is not a duplicate.

[timneutkens]

Duplicate of #257

[rgbkrk]

Sure enough, thanks.

[timneutkens]

🙌 there's some solutions in that thread :)