High CPU on debugging iOS and opening storyboard in Xcode

I’m doing some testing with iOS and found out that, at least on my machine (MacBook Air with Monterey), Fire is running at a quite high CPU load (200%) when debugging. Is this normal?

Also, using the iOS Simple template, trying to edit the Main.Storyboard results in an unresponsive Xcode running at 100%+ without loading it. Opening the LaunchScreen.xib file works ok. Opening a Main.storyboard, in Xcode, from a project created in Xcode loads almost immediately.

Curious. both not issues i’m aware of, I’ll have a look tomorrow

I’ve just tested it on Big Sur; same problem. Also on iMac. Both are Intel.

For comparison: debugging in Xcode, using the same simulator (iOS 15, iPhone 8), takes about 1-2%.

NB: Using build 2674.

This I cant reproduce here. Can I see the exact project, including the /obj folder with the generated .xcproj that shows this for you?

This I haven’t been able to test yet, because Simulator debugging is broken for me for unrelated reasons right now; I’m investigating.

The Simulator is a fickle beast.

I just gte

simctl launch: 2021-10-04 09:09:44.105634-0400 simctl[33988:6280860] +[MTLIOAccelDevice registerDevices]: Zero Metal services found
simctl launch: An error was encountered processing the command (domain=FBSOpenApplicationServiceErrorDomain, code=4):
simctl launch: The request to open "org.me.Multiple Views" failed.
simctl launch: Underlying error (domain=FBSOpenApplicationErrorDomain, code=4):
simctl launch:         The operation couldn’t be completed. Application info provider (FBSApplicationLibrary) returned nil for "org.me.Multiple Views"
simctl launch:         Application info provider (FBSApplicationLibrary) returned nil for "org.me.Multiple Views"
simctl launch: org.me.Multiple Views: -1
simctl launch: exit code 4

no clue why (the apples installed and can be launched manually, fine)

:(. Welcome to Xcode.

Ah, it’s the space in the ID. reproduced.

Logged as bugs://E25386.

You’re referring to the storyboard problem? If so, I don’t have to test further.

Sorry, no. I reproduced the debugging COU load, after fixing the ID

I have attached the project. It’s an unmodified project, created using the iOS template “Simple”.

App11.zip (872,6 KB)

the .xcodeproj opens fine for me, but it seems it cant find the actual files (which is expected, as the Xcode projnhas hardcoded full names, eg /Users/marcvanbreemen/Lokaal/App11/Resources/Main.storyboard):

if I ope the SLn and have it open Xcode from inside Fire, which re-generates the file, irc opens and works fine

no hang, no (unusual; Xcode is always dog slow) delays.

Mmm, strange. I have it on my iMac (Monterey) as well as on my MacBook, which was freshly installed with Big Sur yesterday.

For the record, I’m using the build 2674.

I’m going to test further to see if I can pinpoint my, as it seems, unique situation. If you have any suggestion to look at, let me know :).

BTW: In the screenshot I see that you’ve opened the LaunchScreen. I don’t have a problem with that one. Did you also tested the Main.storyboard? That’s the one I’m having problems with.

Hmm. that one indeed hangs, shows a spinner that just keeps going. Since this reproduces by opening Xcode standalone, not from Fire, this has to be an Apple bug — I suggest filling a radar, and I will too.


BTW: A storyboard created from Xcode doesn’t hang. Maybe a different setting in the one that Fire creates?

Maybe, but isn is a very simple and valid starboard, so Xcode hanging on it is definitely an Xcode bug.

Workaround, yes, would be to just create one in Xcode to replace it, for now (and maybe see what the difference is)

The iOS template “Master/detail” loads fine. I just tested that.

I’m going to test further and see if I can spot the problem in the Simple template. I’ll let you know.

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I’ll replace the Simple one for all 5 languages with this one
Main.storyboard.zip (1.5 KB) but the differences look very academic:

Any ETA for a fix for this “High CPU” bug? As I don’t have a M1 Max (…) my MacBook Air is running hot with this one …

I cannot fix that, aside from suggesting you use the new Storyboard from my previous message.

Since it’s Xcode that’s getting hung up on the bad .storyboard file, and I cannot fix Xcode, the only option is to avoid that file.

The templates(s) do have been updated to use the new one, for 2677.

Sorry, I was referring to the high CPU when debugging in simulator.