This has broken the preview process for all Skip customers (see this discussion for a representative complaint). We have been guarding against ENABLE_PREVIEWS when running our tooling from the Xcode build script, and when that broke in Xcode 16 without warning, everyone's SwiftUI previews went bonkers. Surely there must be some way to prevent running a build script for the preview execution environment? Couldn't there just be a checkbox option to disable running a script when in a preview context? The "Use Legacy Previews Execution" option is not a solution because it will reset on the next Xcode upgrade – again breaking everyone's project without warning.

We have filed feedback FB16424982. For anyone suffering from this regression, please consider filing a Feedback Assistant report referencing that identifier, as it will help bring attention to the problem. There is further discussion about the impact of this issue at https://github.com/orgs/skiptools/discussions/263.