solid-start: [Bug?]: Router "base" property is flaky

UPDATE (moving focus from base prop in vite.config to base prop on Router): For repro instructions, see https://github.com/solidjs/solid-start/issues/1158#issuecomment-1867734373

Duplicates

• I have searched the existing issues

Latest version

• I have tested the latest version

Current behavior 😯

Currently the /_build is the default base path:

https://github.com/solidjs/solid-start/blob/cfe17fa2da37726ef59be347efbef4d8274b74aa/packages/start/config/index.js#L156

Expected behavior 🤔

I expected either / or ‘’ to be the default base path unless set otherwise. If i set it to these values, my routes return nothing.

Steps to reproduce 🕹

• npm create solid.
• choose bare template

set the vite config to:

export default defineConfig({
  base: "/test/"
});

• launch the dev server and go to `http://localhost:3000/test/
• result is that page isn’t found, and that it’s still only on http://localhost:3000

Context 🔦

I’m making a SSG docs site, on a subpath like this example.com/subpath/routes and thus need to set the base to /subpath/

this is to some extend a remake of the now obsolete

• https://github.com/solidjs/solid-start/issues/831#event-11292396040

Your environment 🌎

@solidjs/start 0.4
@solidjs/router 0.10
macos - arm64
chrome 120