Throw an error when trying to resolve a package with a registry and registry manager isn't configured

Author: mattt

Sources/Workspace/Workspace.swift

@@ -1257,9 +1257,11 @@ extension Workspace: PackageContainerProvider {
         }
 
         // If it's a dependency from a package registry
-        if let registryManager = registryManager,
-           let _ = package.identity.scopeAndName
-        {
+        if let _ = package.identity.scopeAndName {
+            guard let registryManager = registryManager else {
+                return completion(.failure(InternalError("registry manager not initialized")))
+            }
+
             let container = RegistryPackageContainer(
                 package: package,
                 identityResolver: identityResolver,
@@ -2693,8 +2695,7 @@ extension Workspace {
             diagnostics.wrap {
                 switch state {
                 case .added(let state), .updated(let state):
-                    if let _ = registryManager,
-                       let _ = packageRef.identity.scopeAndName,
+                    if let _ = packageRef.identity.scopeAndName,
                        case .version(let version) = state.requirement
                     {
                         _ = try downloadSourceArchive(for: packageRef, at: version)