From f0231e287ffb6b1bed7ef37a6f1fdafa37028e6e Mon Sep 17 00:00:00 2001
From: Rintaro Ishizaki <rishizaki@apple.com>
Date: Tue, 2 Jun 2026 11:06:52 -0700
Subject: [PATCH 1/2] Workspace: explicit weak captures in semanticIndexManager
 callbacks

Inner closures captured `sourceKitLSPServer` implicitly. The outer
`Task` already captures it weakly, making it a `var` in scope; inner
@Sendable closures that capture this `var` implicitly trigger the
`SendableClosureCaptures` diagnostic on compiler configurations
without `ImmutableWeakCaptures`.

Add explicit `[weak sourceKitLSPServer]` to each inner closure so the
capture binds cleanly to a fresh weak local.
---
 Sources/SourceKitLSP/Workspace.swift | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Sources/SourceKitLSP/Workspace.swift b/Sources/SourceKitLSP/Workspace.swift
index 97698e44..171b511d 100644
--- a/Sources/SourceKitLSP/Workspace.swift
+++ b/Sources/SourceKitLSP/Workspace.swift
@@ -262,13 +262,13 @@ package final class Workspace: Sendable, BuildServerManagerDelegate {
           hooks: hooks.indexHooks,
           indexTaskScheduler: indexTaskScheduler,
           preparationBatchingStrategy: options.preparationBatchingStrategy,
-          logMessageToIndexLog: {
+          logMessageToIndexLog: { [weak sourceKitLSPServer] in
             sourceKitLSPServer?.logMessageToIndexLog(message: $0, type: $1, structure: $2)
           },
-          indexTasksWereScheduled: {
+          indexTasksWereScheduled: { [weak sourceKitLSPServer] in
             sourceKitLSPServer?.indexProgressManager.indexTasksWereScheduled(count: $0)
           },
-          indexProgressStatusDidChange: {
+          indexProgressStatusDidChange: { [weak sourceKitLSPServer] in
             sourceKitLSPServer?.indexProgressManager.indexProgressStatusDidChange()
           }
         )
@@ -399,7 +399,7 @@ package final class Workspace: Sendable, BuildServerManagerDelegate {
         [weak sourceKitLSPServer] (initializationData, mainFilesChangedCallback) -> (any MainFilesProvider)? in
         await createIndex(
           initializationData: initializationData,
-          indexChangedCallback: {
+          indexChangedCallback: { [weak sourceKitLSPServer] in
             // Notify that main files may have changed.
             await mainFilesChangedCallback()
 

From 1b7f310e92155e0a376701f356fba6504225800a Mon Sep 17 00:00:00 2001
From: Rintaro Ishizaki <rishizaki@apple.com>
Date: Tue, 2 Jun 2026 11:08:51 -0700
Subject: [PATCH 2/2] UncheckedIndex: mark IndexStoreDB? init param as sending

ThreadSafeBox.init takes `consuming sending Value`, so its argument
must be region-isolated. Without `sending` on this init's parameter,
callers in some build configurations couldn't satisfy the sending
requirement and triggered SendingRisksDataRace.
---
 Sources/SemanticIndex/CheckedIndex.swift | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Sources/SemanticIndex/CheckedIndex.swift b/Sources/SemanticIndex/CheckedIndex.swift
index d223d515..ca8069bd 100644
--- a/Sources/SemanticIndex/CheckedIndex.swift
+++ b/Sources/SemanticIndex/CheckedIndex.swift
@@ -344,7 +344,7 @@ package final actor UncheckedIndex: Sendable {
   /// The set of unit output paths that are currently registered in the underlying `IndexStoreDB`.
   private var unitOutputPaths: Set<String> = []
 
-  package init?(_ index: IndexStoreDB?, usesExplicitOutputPaths: Bool) {
+  package init?(_ index: sending IndexStoreDB?, usesExplicitOutputPaths: Bool) {
     guard let index else {
       return nil
     }