I have the same error. I have the following structure (simplified a little), where the packages are local swift packages.
iOS Target
watchOS Target
watchOS Extension Target
Package A
Package B
Package C
The dependencies look something like this for the iOS Target:
iOS Target -> Package A -> Package C
When a scheme for the iOS Target is active, all previews work fine, but when I activate a "Package A" scheme to reduce the build time, then the Xcode Preview Agent crashes because Package A depends on Package C.
jorgenfar
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution