[Upstream #14] Frontend doesn't show error when simulation fails

[ivanzud]

Upstream Issue Mirror

• Upstream issue: Frontend doesn't show error when simulation fails 666ghj/MiroFish#14
• Upstream repository: 666ghj/MiroFish
• State: open
• Author: tt-a1i
• Labels: none
• Last updated: 2026-01-06T06:15:22Z

Summary

What happened When a simulation fails (process crashes, missing deps, etc.), the frontend just sits there showing "running" status with no error message. The backend logs the error correctly and returns runner_status: 'failed' with an error message, but the UI never picks it up. Ran into this while testing locally - took me a while to figure out why nothing was happening. ## Steps to reprodu…

Local Coverage

• Status: covered
• Summary: Step 3 now stops polling and surfaces backend failure text when the simulation runner reports failed, so the UI no longer hangs indefinitely.
• Local refs: frontend/src/components/Step3Simulation.vue, frontend/tests/errors.test.mjs

Recent Upstream Comments

• 666ghj at 2026-01-06T06:15:22Z: I'll investigate this, and you're also welcome to submit a PR first.