# SnapShot shortcut cannot capture Xcode Device Hub on macOS 27 · Issue \#12103 · pingdotgg/t3code

[View on GitCafe](https://git.cafe/pingdotgg/t3code/issues/12103)

Repository: [pingdotgg/t3code](https://git.cafe/pingdotgg/t3code)

Visibility: public

State: backlog

Priority: 0

## Description

[Discussion and activity](https://git.cafe/pingdotgg/t3code/issues/12103)

---

## What happened

On macOS 27, with a simulator open in Xcode's Device Hub, invoking the configured T3 Code SnapShot shortcut consistently fails with “Snapshot failed — The active window is not available for capture.” The reporter supplied a screenshot of the error.

## Diagnosis

The desktop trace records `DesktopSnapShotError` during `desktop.snapShot.prepareCapture`, before macOS capture starts. In the installed revision, `captureSource` throws `window-unavailable` when `activeWindow()` returns no window. The macOS lookup takes `NSWorkspace.frontmostApplication.processIdentifier` and searches the on-screen CoreGraphics window list for a layer-0 window with that owner PID.

A read-only OS probe while Device Hub was frontmost returned `Device Hub` with PID `-1` from `NSWorkspace`, while CoreGraphics listed its visible layer-0 window under PID `35409`. That PID belonged to Xcode's `DeviceHub` executable. The mismatched PIDs explain why the lookup returns no window. The cause of macOS reporting PID `-1` for Device Hub has not been determined.

## Steps to reproduce

1. Open a simulator in Xcode 27's Device Hub on macOS 27.
2. Bring Device Hub to the foreground and invoke the configured T3 Code SnapShot shortcut.
3. Observe “Snapshot failed — The active window is not available for capture.” The reporter says this happens consistently.

## Version

T3 Code Nightly `0.0.43-nightly.20260916.1811` (`ccf220be205f0e509021dbc8cbda90daa638e20d`).

## Environment

macOS 27.0 (build `26A428`), Apple Silicon (`arm64`); Xcode 27.0 (build `27A266a`); T3 Code desktop app. The `t3 triage` CLI ran under Node `v26.8.2`.

## Evidence

```text
2026-09-16 10:52:50 -05:00  desktop.snapShot.prepareCapture  Failure
DesktopSnapShotError: The active window is not available for capture.
  at captureSource (.../apps/desktop/dist-electron/main.cjs:97112:23)

NSWorkspace frontmost application: Device Hub, PID -1
CoreGraphics on-screen layer-0 window: Device Hub, owner PID 35409
PID 35409 executable: /Applications/Xcode.app/Contents/Applications/DeviceHub.app/Contents/MacOS/DeviceHub
```

## Related issues

No matching issue found. #11713 also mentions Device Hub but concerns simulator installation detection, not SnapShot capture.

## Fix applied or workaround

No T3 Code fix applied. A manual macOS window screenshot can be attached to the T3 Code composer as a workaround.

## Filed by

Codex (Astra) via `t3 triage`.