`bun run dev` opens a hidden/invisible window on Windows — window works when `bun --hot app.tsx` is run directly

[luchezarno]

Summary

Running the example app via the documented bun run dev does not visibly open a window on Windows (x64). The process starts, logs [gpuix] created native window and
[gpuix] mount complete,
and renders fine — but the native window is created in a hidden state (IsWindowVisible returns false).
Launching the same app directly with bun --hot app.tsx (or bun app.tsx) shows the window correctly.

Environment

• OS: Windows 10, x64 (Session 1, DWM running)
• GPU: AMD Radeon(TM) Graphics (driver 27.20.14022.3003)
• Bun: 1.4.0 (installed via Scoop)
• GPU iX: @gpuix/react 0.7.0, @gpuix/native 0.7.0, @gpuix/native-win32-x64-msvc 0.7.0
• App: the stock example-app (bunx @gpuix/cli new my-app)

How to reproduce

  bunx @gpuix/cli new my-app
  cd my-app
  bun run dev          # window does not appear

The process stays alive and prints:

  [gpuix] created native window
  [gpuix] mount complete

Enumerating top-level windows with EnumWindows while it runs shows the Todo window exists but is not visible:

  pid=24288 vis=False 'Todo'

If instead you run the script directly:

  bun --hot app.tsx    # window appears (vis=True)

the same window is visible (vis=True) with the correct 940×660 bounds and title Todo.

Suspected cause

The difference is process nesting introduced by the bun run wrapper.

With bun run dev, the app ends up launched 4 processes deep:

  bun.exe run dev  ->  bun.exe --hot app.tsx (shim)  ->  bun.exe --hot app.tsx (real app)

While direct bun --hot app.tsx runs only 2 deep. When the native GPUI window is created from a process launched deep inside the bun run wrapper chain, the window is created but never marked visible (IsWindowVisible == false).

I confirmed --hot is not the culprit: adding a plain script "devplain": "bun app.tsx" and running it via bun run devplain also produces a hidden window, whereas direct bun app.tsx is visible.

Notes / expectations

• The rendered content mounts and the frame loop runs in both cases, so it is a window-visible/activation issue, not a GPU or render failure.
• I also tried a minimal window without titlebarTransparent/windowBackground: 'blurred' and the behavior was identical.
• Is this a known limitation of running GPUI windows from a Bun subprocess (bun run)? Is there anything the native window owner / activation logic could do to make the
  window visible regardless of how deep the launching process is nested?
• Workarounds that work for me: run bun --hot app.tsx directly, or bun run build and run the compiled binary.