My service bot-15m-hl-perp has a reproducible deployment issue tied to Use Metal Build Environment.

Working merged config:

• no buildEnvironment = "V3"

Broken merged config:

• buildEnvironment = "V3"

If I disable Use Metal Build Environment in the UI and click deploy, Railway turns it back on and the merged config again contains buildEnvironment = "V3".

When that happens, the service deploys on the newer Metal/V3 builder path and my runtime process no longer receives required env vars (ENV_VAR_1, ENV_VAR_2), causing startup failure.

/bots/railway.toml is being read correctly and does not contain buildEnvironment = "V3".

This looks like Railway is forcibly re-applying Metal/V3 despite the toggle being disabled.

Working env had NixPack 1.38x and Node v22. Broken one uses Nixpack 1.41 and Node v24.

Build log shows warnings for "SecretsUsedInArgOrEnv: Do not use ARG or ENV instructions for sensitive data" which seem to be red herring (as per some other threads I have seen here)

It seems the env vars are being passed to my service. The deploy logs fail over and over with this error

[bot-15m-hl] {"ts":"2026-04-22T13:50:07.053Z","level":"FATAL","bot":"STAI-15M-HL","msg":"<ENV_VAR_1> and <ENV_VAR_2>must be set","stack":"Error: ENV_VAR_1 and ENV_VAR_2must be set\n at new HlRest (/app/shared/hl_rest.js:287:13)\n at main (/app/bot_15m_hl.js:871:23)\n at Object. (/app/bot_15m_hl.js:2353:3)\n at Module._compile (node:internal/modules/cjs/loader:1760:14)\n at Object..js (node:internal/modules/cjs/loader:1893:10)\n at Module.load (node:internal/modules/cjs/loader:1480:32)\n at Module._load (node:internal/modules/cjs/loader:1299:12)\n at TracingChannel.traceSync (node:diagnostics_channel:328:14)\n at wrapModuleLoad (node:internal/modules/cjs/loader:244:24)\n at Module.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:154:5)"}

Also for the record, both ENV vars are set correctly on the service, so that is not the issue.