Waiting for {simulator/device} to start

Question

With Xcode 9.3 (beta), I'm facing an issue with Xcode tool, while I try to build/run the application (project) for the first time, after Xcode launch/start.

Several times, it prevents project build with the message on status bar:

Waiting for iPhone-X to start

While my simulator is already started and working (There is no any activity, going on, in the simulator).

Here is reference snapshot:

As a temporary solution, I force close Xcode (9.3) and start again.

Is there anyone facing the same issue with Xcode 9.3 beta?

Update: Same issue in Xcode 9.3-Beta 2 also.

Answer 1

I've experienced this lots of times especially in beta releases, until I discovered a 'hack' or perhaps a nice way to prevent such issue. But before that, I might add as well this SO link that has a compilation of .dmg Xcode download links. How to download Xcode DMG or XIP file?

TL;DR In order to prevent this kind of issue, just stop debugging or click on STOP button before building/running your application.

Answer 2

What (most of the time) works for me, is first launch it on a device. Kill it and then run it on a simulator.

Answer 3

Here is How I fixed:

Due to quirks (most likely Simulator bugs) in the Simulator launching on both Xcode 8 and 9, there is no common code to have it launch successfully on both Xcodes. Through experimenting, I have found these to be most reliable:

Xcode 9:

killall Simulator
xcrun simctl boot <device_id>
open `xcode-select -p`/Applications/Simulator.app

Xcode 8:

killall Simulator
xcrun simctl shutdown booted
xcrun instruments -w <device_id>

refer: [iOS 11][Xcode 9] launch, install, start hangs Simulator #209

Answer 4

Make sure you don't have the previous Xcode's version of Simulator running when you attempt to run Simulator from the new Xcode, because Xcode will attempt to use that one. (each Xcode bundles it's own Simulator)

Shut down the old Simulator, and try again.

Also, make sure in Xcode > Preferences > Locations > Command Line Tools is pointing to the current Xcode build.

Answer 5

What worked for me : open the simulator device manually (File -> Open Device -> pick the one). Then restart it by going to Device -> restart. Then try rerunning on xcode.