Xcode 12 is slow when launching apps (even sample projects)

Developer Tools & Services Xcode
terenze OP
Created Jun ’20
Replies 34
Boosts 0
Views 29k
Participants 32
Running a project from Xcode 12 seems to be very slow during launch. Even the example projects from Apple.

Basically it feels as if the app is stuck on the launch screen?

However, if I unplug from my Mac and just launch via tapping on the App icon, it's super fast.

Anyone is having the same issue?
Answered by tundaware in 616750022
This isn't Xcode 12 specific.

Deleting the contents of ~/Library/Developer/Xcode/iOS DeviceSupport seems to be the fix (worked for me just now):
https://developer.apple.com/forums/thread/123068?answerId=420683022#420683022
Replies  34
Boosts  0
Views  29k
Participants  32
tundaware OP
Jun ’20
Same issue. Running my app from Xcode 12 gets stuck on the launch screen for about a minute. Had this same issue during the Xcode 11 beta.
3
tundaware OP
Jun ’20
Accepted Answer
This isn't Xcode 12 specific.

Deleting the contents of ~/Library/Developer/Xcode/iOS DeviceSupport seems to be the fix (worked for me just now):
https://developer.apple.com/forums/thread/123068?answerId=420683022#420683022
34
terenze OP
Jul ’20
Thanks, deleting the contents seem to work for me.
1
chepiok OP
Sep ’20
Same issue for me. Removing iOs DeviceSupport fix the problem for the simulator but when running on a real device (connected to Xcode) it is really slow (stuck on launch screen).
1
legatus OP
Sep ’20
Might be too late, but I ran into this issue after upgrading to Xcode 12.
Going to ~/Library/Developer/Xcode/ and removing contents of "iOS DeviceSupport" did not help so I removed the contents of "iOS Device Logs and "Derived data" too and that resolved it.
0
gruberkristof OP
Sep ’20
Neither deleting Derived Data nor iOS Device Support solved it for me. Any more ideas?
1
M-Chan OP
Sep ’20
Thank, deleting the contents it work.
0
Stokestack OP
Sep ’20
I had this too. It took a full minute for the app to launch on the iPhone from the debugger. The phone screen was blank the whole time, and there was no console output. I have no idea what it was doing.

This behavior mysteriously stopped at some point, and the app now deploys in a reasonable amount of time.
0
Stokestack OP
Sep ’20
I had the same problem. It took a full minute to launch my app on an iPhone from the debugger. The screen was blank the whole time, and there was no debugging-console output. I have no idea what it was doing.

I also have no idea why this behavior suddenly stopped; now the app launches in a reasonable amount of time.
1
Aviametrix OP
Sep ’20
This still happens. I just spent 12 hrs!!!! downloading Xcode 12.01 from the store to replace v12. Now app launches to device take 2 1/2 minutes after launch screen appears. Deleting the specific iOs DeviceSupport folder for the device's version of iOS did the trick. After the folder deletion, Xcode reloaded the symbol tables from the device and all was well. App launch time now back to 1-2 seconds.
2
Jin_90 OP
Sep ’20
1) For simulators run iOS14, delete folders inside ~/Library/Developer/Xcode/iOS DeviceSupport/ (folder's name started with 14.0).

2) For devices run iOS14, select Xcode window tab, click Devices and Simulators, find your device, right-click to unpair the device

https://stackoverflow.com/questions/63929122/slow-app-launch-time-after-updating-to-ios-14-and-xcode-12
1
iamyusufonder OP
Sep ’20
Same issue!
1
Stokestack OP
Oct ’20
Deleting the ~/Library/Developer/Xcode/iOS DeviceSupport directory for iOS 14 did not work for me.
2
MosTwanTedT OP
Oct ’20
Deleting the ~/Library/Developer/Xcode/iOS DeviceSupport directory content did not work for me. And unpairing the devices over the "Devices and Simulators" panel was not helping either. After successfully loading and running the project on Xcode 12, the app hangs nearly a minute on the app launch image and then run perfectly without errors. The long time is enoying and I hope to find a solution soon! I had this issue since Xcode 12 and iOS 14.
2
cabeaulac OP
Oct ’20
Same issue for me. I had to do these instructions 2 times before the app would launch without hanging for a minute.

1) Unpair your phone from xcode
  • Launch xcode with your phone not plugged in
 - plug your phone in
  • under devices in xcode, unpair your phone
2) stop xcode
3) run these
rm -rf ~/Library/Developer/Xcode/iOS\ DeviceSupport
rm -rf ~/Library/Developer/Xcode/iOS\ Device\ Logs
rm -rf ~/Library/Developer/Xcode/DerivedData
4) start xcode
5) plug phone in
11
peterboro OP
Oct ’20
I've been having the same issue since updating to Xcode12 and Xcode12.0.1 didn't fix it. It takes more than a minute from build successful to the app finally completing the launch because it's always stuck on this white screen.
0
waynehend OP
Oct ’20
Still a problem. Xcode Version 12.0 (12A7209)

Per advice here, I deleted the iOS 14 folder inside ~/Library/Developer/Xcode/iOS DeviceSupport.  
(My iPhone is now on 14.0.1, so I left the 13.7 folder alone.)

It took a long time for Xcode to "copy cache files" from the iPhone but once that finally got done, normal build-and-run behavior is back. Nice and snappy.
1
BadinhHanoi OP
Oct ’20
for me, https://stackoverflow.com/questions/63929122/slow-app-launch-time-after-updating-to-ios-14-and-xcode-12

  1. In the XCode menu, Go to Product > Scheme > Edit Scheme

  2. Open the Info tab

  3. Uncheck the Debug executables checkbox

has given.
11
acliyanarachchi OP
Nov ’20
This worked for xcode - 12.2 beta and IOS 14.2

Untick "Debug executable" from below paths worked for me.

  1. Product -> Scheme -> Edit scheme -> Select Run (left column) -> untick "Debug executable"

  2. Product -> Scheme -> Edit scheme -> Select Test (left column) -> untick "Debug executable"

Then close and run again.
10
Shastr OP
Dec ’20
its also could be instruments cache problems
0
fysteven OP
Dec ’20
Still an issue.
0
aureliogiovanni OP
Dec ’20
In my case removing all exceptions break point works fine
1
z3wind OP
Dec ’20
Xcode 12.3 causes this problem for me. Unpairing devices does not resolve the problem.
0
davicedraz OP
Jan ’21
Following exactly these instructions worked for me:

1) Unpair your phone from xcode
Launch xcode with your phone not plugged in
Plug your phone in
Under devices in xcode, unpair your phone
2) stop xcode
3) run these
rm -rf ~/Library/Developer/Xcode/iOS\ DeviceSupport
rm -rf ~/Library/Developer/Xcode/iOS\ Device\ Logs
rm -rf ~/Library/Developer/Xcode/DerivedData
4) start xcode
5) plug phone in
2
Gerald_Oluoch OP
Jan ’21
None of the solutions seems to be working, might be wise to wait for an update from Apple.
1
Xcode 12 is slow when launching apps (even sample projects)
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