dev does not build on Xcode 27. This blocks every open PR and every new one.
What happened
Xcode was updated on this machine at 12:23 on 2026-09-15, mid-session — builds from the same commit succeeded before it and fail after.
The macOS 27 SDK adds a Document protocol to SwiftUI:
SwiftUI.Document:4:17: note: found this candidate
public protocol Document : ReadableDocument, WritableDocument {
InterlinedDomain has exported a Document struct since M4. Any file that imports both — which is every documents-feature view — now has an ambiguous Document in scope.
The errors
Nine sites, six files, all in App/Features/**:
App/Features/AI/AIDocumentSheet.swift:25:21
App/Features/Documents/ConflictBannerView.swift:18:27
App/Features/Documents/DocumentEditorView.swift:24:27
App/Features/Documents/DocumentsListView.swift:15:20
App/Features/Documents/DocumentsListView.swift:24:20
App/Features/Documents/DocumentsListView.swift:106:19
App/Features/Documents/DocumentsRootView.swift:436:21
App/Features/Documents/DocumentsRootView.swift:452:15
App/Features/Documents/DocumentTemplatePickerView.swift:39:21
Every one is import SwiftUI + import InterlinedDomain with a bare Document used as a type.
Note the view models are unaffected — they import Foundation, Observation and InterlinedDomain, not SwiftUI. It is exactly the SwiftUI-importing files, which is what makes the diagnosis unambiguous.
Fix
Qualify the domain type at the use sites: InterlinedDomain.Document.
Considered and rejected:
- Renaming the domain type.
Document is the correct domain name and it is right across the Kit/Domain/Persistence layers and their tests. Renaming a core model to dodge a name collision in one consumer is the tail wagging the dog.
- A module-level
typealias ILDocument = InterlinedDomain.Document. Shorter at the use sites, but it introduces a second name for one concept, and the next reader has to learn that ILDocument and Document are the same thing. Explicit qualification says exactly what it means.
- Dropping
import SwiftUI. Not possible; these are SwiftUI views.
Worth knowing for the future
This is a standing hazard, not a one-off. Any domain type sharing a name with a SwiftUI symbol is one SDK update away from the same break. Current domain models at risk by name: Document, Message, List-adjacent names, Section-adjacent names. Nothing to do pre-emptively, but the diagnosis is worth writing down so the next occurrence takes minutes rather than an afternoon.
Acceptance
xcodebuild build -scheme InterlinedList -destination 'platform=macOS' → ** BUILD SUCCEEDED ** on Xcode 27.- No domain model is renamed.
- The full gate is green.
devdoes not build on Xcode 27. This blocks every open PR and every new one.What happened
Xcode was updated on this machine at 12:23 on 2026-09-15, mid-session — builds from the same commit succeeded before it and fail after.
The macOS 27 SDK adds a
Documentprotocol to SwiftUI:InterlinedDomainhas exported aDocumentstruct since M4. Any file that imports both — which is every documents-feature view — now has an ambiguousDocumentin scope.The errors
Nine sites, six files, all in
App/Features/**:Every one is
import SwiftUI+import InterlinedDomainwith a bareDocumentused as a type.Note the view models are unaffected — they import
Foundation,ObservationandInterlinedDomain, not SwiftUI. It is exactly the SwiftUI-importing files, which is what makes the diagnosis unambiguous.Fix
Qualify the domain type at the use sites:
InterlinedDomain.Document.Considered and rejected:
Documentis the correct domain name and it is right across the Kit/Domain/Persistence layers and their tests. Renaming a core model to dodge a name collision in one consumer is the tail wagging the dog.typealias ILDocument = InterlinedDomain.Document. Shorter at the use sites, but it introduces a second name for one concept, and the next reader has to learn thatILDocumentandDocumentare the same thing. Explicit qualification says exactly what it means.import SwiftUI. Not possible; these are SwiftUI views.Worth knowing for the future
This is a standing hazard, not a one-off. Any domain type sharing a name with a SwiftUI symbol is one SDK update away from the same break. Current domain models at risk by name:
Document,Message,List-adjacent names,Section-adjacent names. Nothing to do pre-emptively, but the diagnosis is worth writing down so the next occurrence takes minutes rather than an afternoon.Acceptance
xcodebuild build -scheme InterlinedList -destination 'platform=macOS'→** BUILD SUCCEEDED **on Xcode 27.