问题
I recently installed Xcode 9.0 GM on my machine. I fired it up to play around and the only simulators I see in the scheme are iPhone 8, iPHone 8 Plus, and iPhone X. I clicked "Download Additional Simulators" thinking the solution would lie there.
I'm greeted with this screen, which is everything I previously had installed.
I dug around on the Apple Developer forum and found this post discussing a similar problem with a prior version of iOS. At the suggestion of one of the posters, I powered down my machine and booted it cold. I opened up Xcode 9.0 again and I have the same issue.
Any suggestions what I can get additional hardware to appear in my Xcode scheme? Thank you for reading.
回答1:
In Xcode 10.3, I also lost all simulators but got them back by running
sudo killall -9 com.apple.CoreSimulator.CoreSimulatorService
回答2:
In case anyone else gets here and are in my situation, I just upgraded to XCode 9.2 and the simulators were all missing, but quitting and relaunching XCode restored them.
回答3:
For me quitting and relaunching XCode also didn't help. So I did the following 3 steps.
Three steps
Step 1:
Product -> Destination -> Download Simulators... Download the simulator(s) you need
Step 2:
Sometimes when you download the new simulator types, they don't automatically show in the list of possible simulators.
Product -> Destination -> Add Additional Simulators... Click the + button in the lower left hand corner, then Add Simulator Give it a name, device type, and the iOS version you just downloaded.
Step 3:
Set proper deployment target. If you have downloaded simulators of lower versions,set the deployment target to the same.
Now it should show up in your list of simulator devices!
回答4:
Delete every single one of the simulators listed in the Devices and Simulators window, one by one, and then start over make new simulators. That always works for me. It's a good idea after any upgrade, in fact.
回答5:
My question was originally answered, but I found a more efficient way to do it with fastlane. Within fastlane, there's a tool called snapshot. The usage is as follows from terminal:
fastlane snapshot reset_simulators
Warning: This will delete all your simulators and replace by new ones! This is useful, if you run into weird problems when running snapshot.
来源：https://stackoverflow.com/questions/46259983/xcode-9-0-simulators-disappeared