Problems serving under path with tailscale serve

[asymmetric]

I want to run yarr behind tailscale serve.

It works well if I serve it at the root (e.g. machine.pango-lin.ts.net), but if I run tailscale serve --set-path foo 7070 (i.e try tro serve it at machine.pango-lin.ts.net/foo, then this happens:

The resource from “https://machine.pango-lin.ts.net/static/javascripts/key.js” was blocked due to MIME type (“text/plain”) mismatch (X-Content-Type-Options: nosniff).

(same for all other JS and CSS files).

Looking at the response headers, the difference between running at / vs at /foo is, that for the latter, the content type is wrong, and a new header is added:

• content-type text/plain; charset=utf-8
• x-content-type-options nosniff.

Any idea where this behavior is coming from?

The version I'm running is the latest stable, v2.4.

[asymmetric]

OK I figured it out, I had to do two things:

• yarr -base foo
• tailscale serve --set-path foo localhost:7070/foo