WIP: Fix product lookup

Author: neonichu

Sources/PackageGraph/PackageGraph+Loading.swift

@@ -267,6 +267,7 @@ private func createResolvedPackages(
 
         var dependencies = OrderedCollections.OrderedDictionary<PackageIdentity, ResolvedPackageBuilder>()
         var dependenciesByNameForTargetDependencyResolution = [String: ResolvedPackageBuilder]()
+        var dependencyNamesForTargetDependencyResolutionOnly = [PackageIdentity: String]()
 
         // Establish the manifest-declared package dependencies.
         package.manifest.dependenciesRequired(for: packageBuilder.productFilter).forEach { dependency in
@@ -334,12 +335,14 @@ private func createResolvedPackages(
 
                 let nameForTargetDependencyResolution = dependency.explicitNameForTargetDependencyResolutionOnly ?? dependency.identity.description
                 dependenciesByNameForTargetDependencyResolution[nameForTargetDependencyResolution] = resolvedPackage
+                dependencyNamesForTargetDependencyResolutionOnly[resolvedPackage.package.identity] = nameForTargetDependencyResolution
 
                 dependencies[resolvedPackage.package.identity] = resolvedPackage
             }
         }
 
         packageBuilder.dependencies = Array(dependencies.values)
+        packageBuilder.dependencyNamesForTargetDependencyResolutionOnly = dependencyNamesForTargetDependencyResolutionOnly
 
         packageBuilder.defaultLocalization = package.manifest.defaultLocalization
 
@@ -441,7 +444,13 @@ private func createResolvedPackages(
 
         let productDependencyMap: [String: ResolvedProductBuilder]
         if lookupByProductIDs {
-            productDependencyMap = productDependencies.spm_createDictionary { ($0.product.identity, $0) }
+            productDependencyMap = productDependencies.spm_createDictionary {
+                guard let packageName = packageBuilder.dependencyNamesForTargetDependencyResolutionOnly[$0.packageBuilder.package.identity] else {
+                    fatalError()
+                }
+                let key = "\(packageName.lowercased())_\($0.product.name)"
+                return (key, $0)
+            }
         } else {
             productDependencyMap = try Dictionary(
                 productDependencies.map { ($0.product.name, $0) },
@@ -467,7 +476,8 @@ private func createResolvedPackages(
             for case .product(let productRef, let conditions) in targetBuilder.target.dependencies {
                 // Find the product in this package's dependency products.
                 // Look it up by ID if module aliasing is used, otherwise by name.
-                let product = lookupByProductIDs ? productDependencyMap[productRef.identity] : productDependencyMap[productRef.name]
+                let key = "\(productRef.package?.lowercased() ?? productRef.name.lowercased())_\(productRef.name)"
+                let product = lookupByProductIDs ? productDependencyMap[key] : productDependencyMap[productRef.name]
                 guard let product else {
                     // Only emit a diagnostic if there are no other diagnostics.
                     // This avoids flooding the diagnostics with product not
@@ -962,6 +972,9 @@ private final class ResolvedPackageBuilder: ResolvedBuilder<ResolvedPackage> {
     /// The dependencies of this package.
     var dependencies: [ResolvedPackageBuilder] = []
 
+    /// Map from package identity to the local name for target dependency resolution that has been given to that package through the dependency declaration.
+    var dependencyNamesForTargetDependencyResolutionOnly: [PackageIdentity: String] = [:]
+
     /// The defaultLocalization for this package.
     var defaultLocalization: String? = nil