How to free up disk space for XCode Beta install

09 September 2021

TL;DR - delete Time Machine local snapshots to free up space.

Does anyone else find installing XCode frustrating? I always need more free disk space, especially when installing a beta. This was the case when I downloaded XCode 13 Beta 5 from the Apple Developer Downloads page. When I tried to extract the xip file I got an error stating:

“The archive XCode_13_beta_5.xip can’t be expanded because the current volume doesn’t have enough free space.”

I deleted XCode simulators and cache files to free up space with the following steps:

Go to Apple icon -> About This Mac
Click on ‘Storage’ tab
Click ‘Manage’ Button
In the Developer menu delete:
- the XCode Cache file
- old iOS and watchOS Device support files

I also delete unused applications, log files, and music to clear up space. After much pruning, I had over 100GB free. Still, the Archive Utility app complained there was not enough free space!

😭😭😭 Why does XCode need so much space?! pic.twitter.com/cowtceXF3h
— Monica Granbois (@mgranbois) September 7, 2021

This seemed odd. I tried the solution proposed in this blog post: Installing Xcode with “not enough disk space available”. It didn’t work for me. But I suggest trying it out.

However, the blog post did lead me to check my disk space using the Disk Utility app (Applications -> Utilities -> Disk Utility). It reported I only had ~25GB free when the “About This Mac” storage screen reported I had ~100GB.

After some googling I found this question on StackExchange: macOS not showing the actual free space. The answers said to delete Time Machine local snapshots. I did so, and boom, the Disk Utility app reported I had 100GB free. I tried the Archive Utility app again. This time it expanded the xip file and installed XCode Beta! Yay!

The commands I used to list and delete the time machine files were (from this answer):

$ tmutil listlocalsnapshots /
com.apple.TimeMachine.2021-08-20-195949.local
com.apple.TimeMachine.2021-09-08-114353.local

 $ tmutil deletelocalsnapshots 2021-08-20-195949
 $ tmutil listlocalsnapshots /
 com.apple.TimeMachine.2021-09-08-114353.local

Why is there a discrepancy between the free space reported by the About This Mac and the Disk Utility apps? Because macOS will automatically delete snapshots when space is needed. So, About This Mac considers the space used by local snapshots as available. Therefore, it reported ~100GB free space. However, the Disk Utility does not consider snapshots as free space. The snapshots are using space so Disk Utility reports that space as used. So, it reported there was only ~25GB of free space.

The Archive Utility also does not consider the storage used by snapshot as free space. It checks for disk space before extracting the file and, in my case, detected that only ~25GB was free. By deleting the local snapshot, it was able to expand the xip file and install XCode Beta.

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