Xcode 9 support on macOS Mojave

Question

With new macOS Mojave coming out tomorrow (24 September 2018), is it going to support Xcode 9?

We could not switch one of our projects to Xcode 10 because of some outdated dependencies.

Solution

Yes.

You can use Xcode 9 (last release is Xcode 9.4.1) on macOS Mojave.

If you are upgrading from macOS High Sierra, you can choose to not update your copy of Xcode installed from the Mac App Store.

If you have already upgrade your App Store installed copy of Xcode to Xcode 10, you can download Xcode 9.4.1 DMG from Apple Developer Downloads.

Once downloaded, double click to mount the DMG, copy Xcode.app from the disk image to Desktop, rename it to Xcode 9.app and move it to /Applications directory. You can also add drag the Xcode 9.app file to Dock to add a shortcut.

Note: I’m not sure about expect version number compatibility, thus recommended to install the last release of Xcode 9, i.e. Xcode 9.4.1.

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As mentioned in your comment, you currently have Xcode 9 installed from the Mac App Store and a GM build of Xcode 10 downloaded from Apple Developer. You can now take either one of the below mentioned approaches. However, before proceeding, consider deleting the Xcode_10.app from /Applications as it is a GM build and the public release for the same is now available:

1. Leave Xcode.app (Xcode 9) as is in the /Applications directory. Mac App Store will show that an update is available. Do not install the update from the Mac App Store. However, make sure that the version of Xcode 9 is the last released version, i.e. Xcode 9.4.1. Download Xcode 10 public build from Apple Developer Download using this link. Copy the Xcode.app from the downloaded DMG to ~/Desktop, rename it to Xcode 10.app and move it to /Applications directory.

2. Second alternative would be to update the Mac App Store installed copy to Xcode 10 and download Xcode 9.4.1 instead from Apple Developer Downloads. Similarly, rename the downloaded file to Xcode 9 and move it to /Applications directory.

Comments

[mikro098]

Currently I've got Xcode.app (9) and Xcode_10.app (10) inside my /Applications. In this case it will be updated automatically or I can leave this naming?

[Nimesh Neema]

@codddeer123 How did you obtain Xcode 10? Is it the public or beta version?

[mikro098]

It's GM version from developer.apple

[mikro098]

I did the 1. version it worked. Both Xcode 9.4.1 and Xcode 10 (release build) however AppStore still shows that Xcode is ready to be updated. Thanks for help

[Nimesh Neema]

@codddeer123 I personally prefer approach #2. Keep things nice and dandy.

[Eljay]

Xcode 10.1 command line update may mess up your installed Xcode 9.4.1. If that happens, you may need to re-install Xcode 9.4.1, and possibly (depending on your project) need to xcode-select (from the command line) the Xcode you need.

[petrosmm]

@Eljay but to confirm, it is possible to harmoniously run Xcode 9 and Xcode together?

[Nimesh Neema]

@petrosmm Yes. Simply install the latest version from the Mac App Store and side load Xcode 9 by downloading from Apple Developer Downloads.

[Eljay]

@petrosmm • For side-by-side Xcodes, I end up nesting Xcode.app in a folder. For example I use the convention /Applications/Xcode_10.1/Xcode.app/... and /Applications/Xcode_9.2/Xcode.app/..., then use command-line sudo xcode-select -s /Applications/Xcode_10.1/Xcode.app to make (in this case) Xcode 10.1 the selected one.

[petrosmm]

@Eljay do you have to select, every time you open x-code or just every time you want to switch the default x-code and it's commandline tools? Or does it depend heavily on what x-code you want to use to write the project you are writing/opening?

[Eljay]

@petrosmm • I usually keep the command line at the most current version. Xcode as an app uses its own version that is bundled with that particular Xcode. The only time I've had it be a (mild) concern is if your Xcode project spawns a shell process that compiles something behind Xcode's back.

[Wayne]

This no longer seems to work. The archive will not open on Mojave. forums.developer.apple.com/thread/125108