XCode 27 - Device Hub replaces Simulator
Author: angelica-snowitCreated Sep 15, 2026Updated Sep 15, 2026
Labelstype: bug 🐞platform: iosstatus: triage
Did you test using the latest Detox?
- I have tested this issue on the latest Detox release and it still reproduces.
Did your test fail and you're not sure why?
- I have read the troubleshooting guide and it didn't help me.
What happened?
It seems impossibile to use latest detox version on Xcode 27:
RUNS e2e/discountsTest.e2e.ts
15:51:10.138 detox[17968] i "open -a Simulator --args -CurrentDeviceUDID 09231F3B-2A7D-418C-8B35-B499B816F86A" failed with error = Error: Command failed: open -a Simulator --args -CurrentDeviceUDID 09231F3B-2A7D-418C-8B35-B499B816F86A
Unable to find application named 'Simulator'
(code=1), stdout and stderr:
15:51:10.138 detox[17968] i
15:51:10.138 detox[17968] i Unable to find application named 'Simulator'
15:51:10.138 detox[17968] i Unable to open the Simulator app. Please make sure you have Xcode and iOS Simulator installed (https://developer.apple.com/xcode/). In case you already have the latest Xcode version installed, try run the command: `sudo xcode-select -s /Applications/Xcode.app`. If you are running tests from CI, we recommend running them with "--headless" device configuration (see: https://wix.g
RUNS e2e/discountsTest.e2e.ts
15:52:24.150 detox[17968] i Caught unhandled error:
error: Action dispatched too early, there is no session to use:
[...]
The pending request #1 ("waitForActive") has been rejected due to the following error:
The app has unexpectedly disconnected from Detox server.What was the expected behaviour?
No response
Help us reproduce this issue!
No response
In what environment did this happen?
Detox version: v20.51.4 React Native version: v0.86.2 Has Fabric (React Native's new rendering system) enabled: (yes/no) yes Node version: v24.14.1 Device model: Simulator (Device Hub) - iPhone 17 iOS version: 27.0 macOS version: v26.6.2 Xcode version: v27.0 Test-runner (select one): jest
Source: wix/Detox