Xcode stuck at 100% while downloading.

Howdy hazar2000,

Thanks for posting in the Apple Support Communities.

Let's first confirm that you're up to date with the latest macOS version to see if that could be related to the install not completing. If an update is available, be sure you have a recent backup of information prior to installing. The steps below will help with this process, and you can find additional information here: Update macOS on Mac

Before you get started, it's a good idea to back up your Mac. Then follow these steps to find and install any available software updates or upgrades.

1. From the Apple menu  in the corner of your screen, choose System Preferences.

2. In the System Preferences window, click Software Update.


If your System Preferences doesn't include Software Update, learn how to upgrade to macOS Monterey or upgrade to an older macOS, and use the Updates tab of the App Store app to get app updates.

3. Click Update Now or Upgrade Now:

• Update Now installs the latest updates for the currently installed version, such as an update from macOS Big Sur 11.5 to macOS Big Sur 11.6. 

• Upgrade Now installs a major new version with a new name, such as macOS Monterey. Software Update shows only upgrades that are compatible with your Mac.

If you're up to date with the current macOS version, confirm that you don't have an additional installation of the software with an older version already. If you do, you may need to remove that to complete this installation. Also, try a restart to see if that may clear this up: Shut down or restart your Mac

We hope this is able to help.

Have a great day!

I'm seeing the same thing here (MacOS 12.3.1 (21E258) MacBook Air (M1, 2020).

Restarted multiple times - no change....