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Node + tsx “__name is not a function” crash

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Summary

Running Fased via Node with tsx fails at startup with: 
[fased] Failed to start CLI: TypeError: __name is not a function
    at createSubsystemLogger (.../src/logging/subsystem.ts:203:25)
    at .../src/agents/auth-profiles/constants.ts:25:20
This was observed on direct node --import tsx ... developer paths. The same runtime path works when Fased is built first and launched through the compiled entrypoint. This is a developer-runner issue for direct node --import tsx ... paths. It is not the normal installed Fased runtime path; the supported runner builds with tsdown when needed and launches fased.mjs. For normal install requirements, see Node.js.

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Environment

  • Node: v25.x (observed on v25.3.0)
  • tsx: 4.21.0
  • OS: macOS (repro also likely on other platforms that run Node 25)

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Repro (Node-only)

# in repo root
node --version
pnpm install
node --import tsx src/entry.ts status

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Minimal repro in repo

node --import tsx scripts/repro/tsx-name-repro.ts

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Node version check

  • Node 25.3.0: fails
  • Node 22.22.0 (Homebrew node@22): fails
  • Node 24: needs verification on the local machine where the crash appears

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Notes / hypothesis

  • tsx uses esbuild to transform TS/ESM. esbuild’s keepNames emits a __name helper and wraps function definitions with __name(...).
  • The crash indicates __name exists but is not a function at runtime, which implies the helper is missing or overwritten for this module in the Node 25 loader path.
  • Similar __name helper issues have been reported in other esbuild consumers when the helper is missing or rewritten.

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Workarounds

  • Use the normal runner scripts instead of direct node --import tsx: 
    pnpm fased status
pnpm gateway:watch
  • Or build first, then run compiled output: 
    pnpm build:fast
node --watch fased.mjs status
  • Confirmed locally: compiled output plus node fased.mjs status works on Node 25.
  • Disable esbuild keepNames in the TS loader if possible (prevents __name helper insertion); tsx does not currently expose this.
  • Test Node LTS with tsx to confirm whether the issue is local to a specific Node/loader combination.

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References

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Next steps

  • Repro on the supported Node LTS line and the newest local Node version.
  • Test tsx nightly or pin to earlier version if a known regression exists.
  • If reproduces on Node LTS, file a minimal repro upstream with the __name stack trace.