"vitest --ui" causing "Error: spawn xdg-open ENOENT" - node.js

Question

I'm trying to check out Vitest's fancy UI server in my node docker container. But can't get it up and running. When running the npm script vitest --ui I get a node error spawn xdg-open ENOENT.
Here the full error message:
$ npm run test-ui
> wpvite#0.0.0 test-ui
> vitest --ui
DEV v0.23.4 /home/node/apps/main/frontend
UI started at http://localhost:51204/__vitest__/
node:events:491
throw er; // Unhandled 'error' event
^
Error: spawn xdg-open ENOENT
at ChildProcess._handle.onexit (node:internal/child_process:283:19)
at onErrorNT (node:internal/child_process:476:16)
at process.processTicksAndRejections (node:internal/process/task_queues:82:21)
Emitted 'error' event on ChildProcess instance at:
at ChildProcess._handle.onexit (node:internal/child_process:289:12)
at onErrorNT (node:internal/child_process:476:16)
at process.processTicksAndRejections (node:internal/process/task_queues:82:21) {
errno: -2,
code: 'ENOENT',
syscall: 'spawn xdg-open',
path: 'xdg-open',
spawnargs: [ 'https://localhost:51204/__vitest__/' ]
}
Node.js v18.10.0
Google is no help at all - nothing related to Vitest even close. Also I'm obviously not a Node.js expert.

Answer 1

Even though the Node.js error message appears pretty cryptic to me, I still was lucky to use Ubuntu as my primary OS (beside macOS) which made me draw my attention to xdg-open in the error message - I occasionally use the command to open all kind of programs/apps on Ubuntu. Don't know why, but you need to have xdg-open installed on your system, to be able to run vitest --ui, even though it's neither mentioned in Vitest nor in Vite Github repos with a single word. Anyway for debian based containers it's:
apt install xdg-utils --fix-missing
Allthough this made the ENOENT error go away and the UI server starts up without errors, I still don't get to see the UI app due to some runtime-dom errors... I give it up. But maybe someone else finds the xdg-open info helpful.
UPDATE: It's working!
I just had to append /__vitest__/ to my proxied local url as clearly described in the docs:
"Then you can visit the Vitest UI at http://localhost:51204/__vitest__/"