ios - Xcode 11 debugger is extremely slow - A known problem?

Question

Since I updated to the latest Xcode version 11.0 (11A420a) the debugging is extremely slow and cumbersome.

EDIT: After updating to 11.1 GM (11A1027) the problem is still the same.

Compiling a project and running it in simulator or on a device is no problem. However when reaching a breakpoint Xcode becomes more or less unusable:

• Program execution stops immediately when the breakpoint is reached. However Xcode needs up to 30 seconds to show the position in the code window and another minute or so to load the content of the variable view (which shows the values and states of the variables available at the breakpoint).
• If I use the Step into or Step over features it takes up to a minute to perform the next step and again another minute to load the variables.

I am running Xcode on a Mac mini 2018 with a 3.2 GHz i7 and 32 GB ram. I have used Xcode 10 on the same machine before without any problems.

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Searching for "Xcode slow" brings up a ton of threads and possible solutions of course. From my years as iOS Developer I know that Xcode never was the fastest and stable program. However it was never as bad as now.

Unfortunately none of the know tricks (restarting Xcode or the Mac, cleaning the project, cleaning the Xcode library folders, etc. had any effect,

So the big question is:

Is this a known problem in Xcode 11? Are there any known solutions?

Answer 1

Well I had the same problem and recently figured out that I just forgot to disable diagnostics for my scheme

Open your run configurations -> Manage schemes -> Edit scheme -> Run -> Diagnostics tab