Cannot read properties of undefined (reading 'length')

Describe the bug

It took me forever to debug an error because the error message got lost by the router. Demonstration:

function throwError(): string {
  throw new Error('A meaningful error message');
}

<Route
  path={throwError()}
  element={<div>hello</div>}
/>

This leads to the following error:

Uncaught TypeError: Cannot read properties of undefined (reading 'length')
at components.jsx:40:43
at dev.js:453:34
at untrack (dev.js:434:12)
at Object.fn (dev.js:453:20)
at runComputation (dev.js:696:22)
at updateComputation (dev.js:679:3)
at Object.readSignal (dev.js:612:67)
at get when [as when] (components.jsx:64:25)
at Show.createMemo.equals [as fn] (dev.js:1443:44)
at runComputation (dev.js:696:22)

The original error message ('A meaningful error message') got lost.

Platform

• OS: Windows
• Browser: Chrome 113
• Solid: 1.7.6
• Solid router: 0.8.2

Start by reproducing the throwing path shown in the issue and inspect the router code involved in the components.jsx stack trace, especially the handling of route evaluation errors. Confirm that the original error message, “A meaningful error message,” is preserved instead of being replaced by the undefined-length TypeError.