Change compatibilityVersion to Xcode 10.0

[acecilia]

I experienced that with the compatibilityVersion set to Xcode 9.3, Xcode automatically sets the ObjectVersion from 51 to 50.

[yonaskolb]

Interesting. Is the downgrade in object version affecting you?
I wonder if anyone is still using Xcode 9.3 with the latest XcodeGen, probably not

[acecilia]

Yes it is. I am not sure at which point is happening (I did some tests but could not figure out in which exact moment Xcode decides to update the ObjectVersion), but after working with a project for some time and going to commit, I see that ObjectVersion changed from 51 to 50.

To check this you can make a test:

• Create a new Single View App project with Xcode 10.2.1 (10E1001). It will be created with ObjectVersion = 50 and compatibilityVersion = "Xcode 9.3".
• With the project file selected, in the file inspector (using the dropdown) change the compatibility to Xcode 10.0-compatible: the ObjectVersion is automatically changed to 51.
• Changing the compatibility back to Xcode 9.3-compatible also automatically changes the ObjectVersion to 50.

Due to that, seems that ObjectVersion = 51 is only used with compatibilityVersion = "Xcode 10.0". So, another option I guess is to keep compatibilityVersion = "Xcode 9.3" and ObjectVersion = 50.