Retrieve resolved package versions in parallel

Author: fortmarek

Sources/Workspace/Workspace+Dependencies.swift

@@ -419,26 +419,31 @@ extension Workspace {
         }
 
         // Retrieve the required resolved packages.
-        for resolvedPackage in requiredResolvedPackages {
-            await observabilityScope.makeChildScope(
-                description: "retrieving resolved package versions for dependencies",
-                metadata: resolvedPackage.packageRef.diagnosticsMetadata
-            ).trap {
-                switch resolvedPackage.packageRef.kind {
-                case .localSourceControl, .remoteSourceControl:
-                    _ = try await self.checkoutRepository(
-                        package: resolvedPackage.packageRef,
-                        at: resolvedPackage.state,
-                        observabilityScope: observabilityScope
-                    )
-                case .registry:
-                    _ = try await self.downloadRegistryArchive(
-                        package: resolvedPackage.packageRef,
-                        at: resolvedPackage.state,
-                        observabilityScope: observabilityScope
-                    )
-                default:
-                    throw InternalError("invalid resolved package type \(resolvedPackage.packageRef.kind)")
+        await withThrowingTaskGroup(of: Void.self) { taskGroup in
+            for resolvedPackage in requiredResolvedPackages {
+                let observabilityScope = observabilityScope.makeChildScope(
+                    description: "retrieving resolved package versions for dependencies",
+                    metadata: resolvedPackage.packageRef.diagnosticsMetadata
+                )
+                taskGroup.addTask {
+                    await observabilityScope.trap {
+                        switch resolvedPackage.packageRef.kind {
+                        case .localSourceControl, .remoteSourceControl:
+                            _ = try await self.checkoutRepository(
+                                package: resolvedPackage.packageRef,
+                                at: resolvedPackage.state,
+                                observabilityScope: observabilityScope
+                            )
+                        case .registry:
+                            _ = try await self.downloadRegistryArchive(
+                                package: resolvedPackage.packageRef,
+                                at: resolvedPackage.state,
+                                observabilityScope: observabilityScope
+                            )
+                        default:
+                            throw InternalError("invalid resolved package type \(resolvedPackage.packageRef.kind)")
+                        }
+                    }
                 }
             }
         }