Xcode build target difference - arm64 and armv7, arm64

Question

I had created 2 new projects on Xcode this week for 2 different apps. For some reason one of the project always fails compiling for the device target. I then realized that the device target is different for both the project. For the working project "Any iOS Project (arm64)" The project which fails to build has "Any iOS Project (armv7, arm64)"

What causes the device target to change this way and what is the difference?

Answer 1

armv7 is 32bit architecture that was supported by earlier iOS versions up till 10.3.4. arm64 is 64bit architecture which is supported by newer devices.

If your project has minimum iOS version which is below iOS 11.0, Xcode will automatically pick both armv7 and arm64.

In case if Xcode does not pick the required architecture automatically, it can be added in build settings as shown below: