Regardless of whether I've changed any code or not, the XCode build goes in a few seconds sometimes and other times takes a minute or two... any idea what might be holding up the script? Thanks,

I have not measured this, but I think that the variability may be due to whether or not the VM system drops the xcodebuild executable (+ frameworks) from RAM between runs. I've observed that if I do a number of quick build-run-edit cycles in a row, it tends to be fast. If do a build and then perform a lot of memory intensive activities, the next build takes longer.

The Xcode app itself may have an advantage here in that the Xcode frameworks don't need to be reloaded every time (and it can cache data structures that xcodebuild would need to rebuild every time).

Chris