Xcode 12 spinning beach balls all the time

Here are some things people can try.
1: unpair devices.
2: use lighting cable, not network.
3: run Xcode in Rosetta (if on M1)
4: Write Apple!!!!!!

Yep, all day all week now. It's literally been unusable on my 2018 MBP i9 since the 12.3 update. AppCode has no such issues, so I've been able to do MOST of what I need without launching Xcode, but anything on a XIB or storyboard is a lost cause now.

I've had to force close Xcode every time I dare to launch it this week.

Xcode 12.1 seems to be ok, 12.3 and 12.4 are very bad for beach ball, especially when using Interface Builder and "Varying Traits".

Any fix for this? Every time I change something I get the beach ball... it's unusable :(

I've been getting persistent beach balls in Xcode version 12.3 and 12.4. For me, the culprit has always turned out to be my connected iPhone – I can either wait out the current beach ball and unpair it in the Devices window, or I can simply disconnect the Lightning cable and the beach ball stops immediately. Yikes.

1. was fine for me but 12.4 has ground me to a halt! (15" MB Pro 2018 2.9ghz i9 32 GB Ram) I haven't narrowed it down to anything in particular.

The same thing is now happening with the current Xcode Version and the M1 MacBook Pro. I had to install the 12.5 beta to get it running reliably again...

This is happening all the time with me on Xcode 12.4 and Catalina 10.5.17, iMac 2012. Disabling the wifi seems to bring it back to life. What has happened to Xcode quality control ?

I was getting this frequently also running Xcode 12.4 and Mac Air M1.  

Starfia's suggestion of disabling/removing the my networked iPhone seems to have helped. Suggest others try that at a minimum.

For me this was happening until I unchecked Connect via network on the iPhone I'd previously set up that way. After that the beach ball problem went away.

I also had this problem using Xcode 12.4.

Following other suggestions here, I deleted my real devices from Xcode. That alone didn't fix it. But as others here have suggested, I re-added my devices and set them up as they had been set up before. And that worked. No more beach balls.

Same here (Xcode 12.4, 12D4e) , especially immediately after starting up my computer (fastest Mac mini 2018) which is switched off during the night. It occurs to me:

• beach balls occur even without any file or project open. Xcode just stops responding while seemingly doing nothing. No disk, CPU or network activity can be seen.
• if I wait it out (for instance 10 minutes) the beach balls will eventually finish and Xcode continues to work as normal.
• if I wait it out (which is unbearable), the beach balls mostly will not come back until the next morning.
• if I force quit Xcode, sometimes a couple of times in sequence, the problem is gone in most cases.
• when Time Machine is doing stuff, beachballs take much longer to disappear.
• unpairing all devices and re-adding them does not seem to help.
• not using network but only lightning connections for devices does not seem to help.
• cleaning out all caches, derived data, etc does not help.

It's just terrible. I am afraid to open a new project or switch projects in Xcode because that seems to mean another early lunch break. I am afraid to open a storyboard or nib file because that may trigger another forced 10 minute wait.

Still seeing this on my M1 Pro Mac. Version 13.4 of XCode but I can't even open projects. The beachball starts and doesn't stop as soon as I try to open a project.