diff --git a/Sources/PackageGraph/ModulesGraph+Loading.swift b/Sources/PackageGraph/ModulesGraph+Loading.swift
index 2ea14951129..1435795840c 100644
--- a/Sources/PackageGraph/ModulesGraph+Loading.swift
+++ b/Sources/PackageGraph/ModulesGraph+Loading.swift
@@ -728,23 +728,10 @@ private func createResolvedPackages(
             moduleBuilder.dependencies += implicitSystemLibraryDeps.map { .module($0, conditions: []) }
 
             // Establish product dependencies.
-            for case .product(let productRef, let conditions) in moduleBuilder.module.dependencies {
+            for case .product(let productRef, var conditions) in moduleBuilder.module.dependencies {
                 if let package = productRef.package, prebuilts[.plain(package)]?[productRef.name] != nil {
-                    // See if we're using a prebuilt instead
-                    if moduleBuilder.module.type == .macro {
-                        continue
-                    } else if moduleBuilder.module.type == .test {
-                        // use prebuilt if this is a test that depends a macro target
-                        // these are guaranteed built for host
-                        if moduleBuilder.module.dependencies.contains(where: { dep in
-                            guard let module = dep.module else {
-                                return false
-                            }
-                            return module.type == .macro
-                        }) {
-                            continue
-                        }
-                    }
+                    // Only use the dependency if not on host
+                    conditions.append(.host(.init(isHost: false)))
                 }
 
                 // Find the product in this package's dependency products.
diff --git a/Sources/PackageGraph/Resolution/ResolvedModule.swift b/Sources/PackageGraph/Resolution/ResolvedModule.swift
index 786a61b7c28..23d89ce3d11 100644
--- a/Sources/PackageGraph/Resolution/ResolvedModule.swift
+++ b/Sources/PackageGraph/Resolution/ResolvedModule.swift
@@ -288,7 +288,12 @@ extension ResolvedModule: Identifiable {
         public var targetName: String { self.moduleName }
 
         public let moduleName: String
-        let packageIdentity: PackageIdentity
+        public let packageIdentity: PackageIdentity
+
+        public init(moduleName: String, packageIdentity: PackageIdentity) {
+            self.moduleName = moduleName
+            self.packageIdentity = packageIdentity
+        }
     }
 
     public var id: ID {
diff --git a/Sources/PackageLoading/PackageBuilder.swift b/Sources/PackageLoading/PackageBuilder.swift
index 08535c82807..2943ef8bd80 100644
--- a/Sources/PackageLoading/PackageBuilder.swift
+++ b/Sources/PackageLoading/PackageBuilder.swift
@@ -1407,40 +1407,39 @@ public final class PackageBuilder {
             table.add(assignment, for: .SWIFT_ACTIVE_COMPILATION_CONDITIONS)
         }
 
-        // Add in flags for prebuilts if the target is a macro or a macro test.
-        // Currently we only support prebuilts for macros.
-        if target.type == .macro || target.isMacroTest(in: manifest) {
-            let prebuiltLibraries: [String: PrebuiltLibrary] = target.dependencies.reduce(into: .init()) {
-                guard case let .product(name: name, package: package, moduleAliases: _, condition: _) = $1,
-                      let package = package,
-                      let prebuilt = prebuilts[.plain(package)]?[name]
-                else {
-                    return
-                }
-
-                $0[prebuilt.libraryName] = prebuilt
+        // Add in flags for prebuilts on host
+        let prebuiltLibraries: [String: PrebuiltLibrary] = target.dependencies.reduce(into: .init()) {
+            guard case let .product(name: name, package: package, moduleAliases: _, condition: _) = $1,
+                  let package = package,
+                  let prebuilt = prebuilts[.plain(package)]?[name]
+            else {
+                return
             }
 
-            for prebuilt in prebuiltLibraries.values {
-                let lib = prebuilt.path.appending(components: ["lib", "lib\(prebuilt.libraryName).a"]).pathString
-                var ldFlagsAssignment = BuildSettings.Assignment()
-                ldFlagsAssignment.values = [lib]
-                table.add(ldFlagsAssignment, for: .OTHER_LDFLAGS)
+            $0[prebuilt.libraryName] = prebuilt
+        }
 
-                var includeDirs: [AbsolutePath] = [prebuilt.path.appending(component: "Modules")]
-                if let checkoutPath = prebuilt.checkoutPath, let includePath = prebuilt.includePath {
-                    for includeDir in includePath {
-                        includeDirs.append(checkoutPath.appending(includeDir))
-                    }
-                } else {
-                    for cModule in prebuilt.cModules {
-                        includeDirs.append(prebuilt.path.appending(components: "include", cModule))
-                    }
+        for prebuilt in prebuiltLibraries.values {
+            let lib = prebuilt.path.appending(components: ["lib", "lib\(prebuilt.libraryName).a"]).pathString
+            var ldFlagsAssignment = BuildSettings.Assignment()
+            ldFlagsAssignment.values = [lib]
+            ldFlagsAssignment.conditions = [.host(.init(isHost: true))]
+            table.add(ldFlagsAssignment, for: .OTHER_LDFLAGS)
+
+            var includeDirs: [AbsolutePath] = [prebuilt.path.appending(component: "Modules")]
+            if let checkoutPath = prebuilt.checkoutPath, let includePath = prebuilt.includePath {
+                for includeDir in includePath {
+                    includeDirs.append(checkoutPath.appending(includeDir))
+                }
+            } else {
+                for cModule in prebuilt.cModules {
+                    includeDirs.append(prebuilt.path.appending(components: "include", cModule))
                 }
-                var includeAssignment = BuildSettings.Assignment()
-                includeAssignment.values = includeDirs.map({ "-I\($0.pathString)" })
-                table.add(includeAssignment, for: .OTHER_SWIFT_FLAGS)
             }
+            var includeAssignment = BuildSettings.Assignment()
+            includeAssignment.values = includeDirs.map({ "-I\($0.pathString)" })
+            includeAssignment.conditions = [.host(.init(isHost: true))]
+            table.add(includeAssignment, for: .OTHER_SWIFT_FLAGS)
         }
 
         return table
diff --git a/Sources/PackageModel/BuildEnvironment.swift b/Sources/PackageModel/BuildEnvironment.swift
index d6545c46166..d55c05bdc6f 100644
--- a/Sources/PackageModel/BuildEnvironment.swift
+++ b/Sources/PackageModel/BuildEnvironment.swift
@@ -13,10 +13,12 @@
 /// A build environment with which to evaluate conditions.
 public struct BuildEnvironment {
     public let platform: Platform
+    public let isHost: Bool
     public let configuration: BuildConfiguration?
 
-    public init(platform: Platform, configuration: BuildConfiguration? = nil) {
+    public init(platform: Platform, isHost: Bool, configuration: BuildConfiguration? = nil) {
         self.platform = platform
         self.configuration = configuration
+        self.isHost = isHost
     }
 }
diff --git a/Sources/PackageModel/Manifest/PackageConditionDescription.swift b/Sources/PackageModel/Manifest/PackageConditionDescription.swift
index b8257bc5650..04930e1dba9 100644
--- a/Sources/PackageModel/Manifest/PackageConditionDescription.swift
+++ b/Sources/PackageModel/Manifest/PackageConditionDescription.swift
@@ -30,6 +30,7 @@ public enum PackageCondition: Hashable, Sendable {
     case platforms(PlatformsCondition)
     case configuration(ConfigurationCondition)
     case traits(TraitCondition)
+    case host(HostCondition)
 
     public func satisfies(_ environment: BuildEnvironment) -> Bool {
         switch self {
@@ -39,6 +40,8 @@ public enum PackageCondition: Hashable, Sendable {
             return platforms.satisfies(environment)
         case .traits(let traits):
             return traits.satisfies(environment)
+        case .host(let host):
+            return host.satisfies(environment)
         }
     }
 
@@ -107,9 +110,7 @@ public struct ConfigurationCondition: Hashable, Sendable {
     }
 }
 
-
-/// A configuration condition implies that an assignment is valid on
-/// a particular build configuration.
+/// A traits condition implies that an assignment is valid in the given build environment
 public struct TraitCondition: Hashable, Sendable {
     public let traits: Set<String>
 
@@ -122,3 +123,15 @@ public struct TraitCondition: Hashable, Sendable {
     }
 }
 
+/// A host condition determines whether the build environment is for host
+public struct HostCondition: Hashable, Sendable {
+    public let isHost: Bool
+
+    public init(isHost: Bool) {
+        self.isHost = isHost
+    }
+
+    public func satisfies(_ environment: BuildEnvironment) -> Bool {
+        environment.isHost == isHost
+    }
+}
diff --git a/Sources/SPMBuildCore/BuildParameters/BuildParameters.swift b/Sources/SPMBuildCore/BuildParameters/BuildParameters.swift
index 6bd5b8804c1..e7ab8fa743c 100644
--- a/Sources/SPMBuildCore/BuildParameters/BuildParameters.swift
+++ b/Sources/SPMBuildCore/BuildParameters/BuildParameters.swift
@@ -90,7 +90,7 @@ public struct BuildParameters: Encodable {
 
     /// The current build environment.
     public var buildEnvironment: BuildEnvironment {
-        BuildEnvironment(platform: currentPlatform, configuration: configuration)
+        BuildEnvironment(platform: currentPlatform, isHost: destination == .host, configuration: configuration)
     }
 
     /// The current platform we're building for.
diff --git a/Sources/SwiftBuildSupport/PackagePIFBuilder+Helpers.swift b/Sources/SwiftBuildSupport/PackagePIFBuilder+Helpers.swift
index b409518837d..e6ac743d571 100644
--- a/Sources/SwiftBuildSupport/PackagePIFBuilder+Helpers.swift
+++ b/Sources/SwiftBuildSupport/PackagePIFBuilder+Helpers.swift
@@ -28,6 +28,7 @@ import enum PackageModel.BuildConfiguration
 import enum PackageModel.BuildSettings
 import class PackageModel.ClangModule
 import struct PackageModel.ConfigurationCondition
+import struct PackageModel.HostCondition
 import class PackageModel.Manifest
 import class PackageModel.Module
 import enum PackageModel.ModuleMapType
@@ -255,12 +256,14 @@ extension Sequence<PackageModel.PackageCondition> {
         var platformConditions: [PackageModel.PlatformsCondition] = []
         var configurationConditions: [PackageModel.ConfigurationCondition] = []
         var traitConditions: [PackageModel.TraitCondition] = []
+        var hostConditions: [PackageModel.HostCondition] = []
 
         for packageCondition in self {
             switch packageCondition {
             case .platforms(let condition): platformConditions.append(condition)
             case .configuration(let condition): configurationConditions.append(condition)
             case .traits(let condition): traitConditions.append(condition)
+            case .host(let condition): hostConditions.append(condition)
             }
         }
 
diff --git a/Tests/BuildTests/BuildPlanTests.swift b/Tests/BuildTests/BuildPlanTests.swift
index a27d2f178f0..4abe77b13d9 100644
--- a/Tests/BuildTests/BuildPlanTests.swift
+++ b/Tests/BuildTests/BuildPlanTests.swift
@@ -957,6 +957,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
             let plan = try await mockBuildPlan(
                 environment: BuildEnvironment(
                     platform: .linux,
+                    isHost: true,
                     configuration: .release
                 ),
                 graph: graph,
@@ -999,6 +1000,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
             let plan = try await mockBuildPlan(
                 environment: BuildEnvironment(
                     platform: .macOS,
+                    isHost: true,
                     configuration: .debug
                 ),
                 graph: graph,
@@ -1507,6 +1509,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
             let result = try await BuildPlanResult(plan: mockBuildPlan(
                 environment: BuildEnvironment(
                     platform: .linux,
+                    isHost: true,
                     configuration: .release
                 ),
                 graph: graph,
@@ -1526,6 +1529,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
             let result = try await BuildPlanResult(plan: mockBuildPlan(
                 environment: BuildEnvironment(
                     platform: .macOS,
+                    isHost: true,
                     configuration: .debug
                 ),
                 graph: graph,
@@ -2106,6 +2110,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
             let plan = try await mockBuildPlan(
                 environment: BuildEnvironment(
                     platform: .linux,
+                    isHost: true,
                     configuration: .release
                 ),
                 graph: graph,
@@ -3568,7 +3573,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
         let graphResult = PackageGraphResultXCTest(graph)
 
         do {
-            let linuxDebug = BuildEnvironment(platform: .linux, configuration: .debug)
+            let linuxDebug = BuildEnvironment(platform: .linux, isHost: true, configuration: .debug)
             try graphResult.check(reachableBuildProducts: "aexec", "BLibrary1", "BLibrary2", in: linuxDebug)
             try graphResult.check(reachableBuildTargets: "ATarget", "BTarget1", "BTarget2", in: linuxDebug)
 
@@ -3583,7 +3588,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
         }
 
         do {
-            let macosDebug = BuildEnvironment(platform: .macOS, configuration: .debug)
+            let macosDebug = BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
             try graphResult.check(reachableBuildProducts: "aexec", "BLibrary2", in: macosDebug)
             try graphResult.check(reachableBuildTargets: "ATarget", "BTarget2", "BTarget3", in: macosDebug)
 
@@ -3598,7 +3603,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
         }
 
         do {
-            let androidRelease = BuildEnvironment(platform: .android, configuration: .release)
+            let androidRelease = BuildEnvironment(platform: .android, isHost: false, configuration: .release)
             try graphResult.check(reachableBuildProducts: "aexec", "CLibrary", in: androidRelease)
             try graphResult.check(reachableBuildTargets: "ATarget", "CTarget", in: androidRelease)
 
@@ -4905,7 +4910,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
         // Test debug configuration
         do {
             let result = try await BuildPlanResult(plan: mockBuildPlan(
-                environment: BuildEnvironment(platform: .macOS, configuration: .debug),
+                environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug),
                 graph: graph,
                 fileSystem: fs,
                 observabilityScope: observability.topScope
@@ -4927,7 +4932,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
         // Test release configuration
         do {
             let result = try await BuildPlanResult(plan: mockBuildPlan(
-                environment: BuildEnvironment(platform: .macOS, configuration: .release),
+                environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .release),
                 graph: graph,
                 fileSystem: fs,
                 observabilityScope: observability.topScope
@@ -4993,7 +4998,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
         // Test debug configuration
         do {
             let result = try await BuildPlanResult(plan: mockBuildPlan(
-                environment: BuildEnvironment(platform: .macOS, configuration: .debug),
+                environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug),
                 graph: graph,
                 fileSystem: fs,
                 observabilityScope: observability.topScope
@@ -5011,7 +5016,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
         // Test release configuration
         do {
             let result = try await BuildPlanResult(plan: mockBuildPlan(
-                environment: BuildEnvironment(platform: .macOS, configuration: .release),
+                environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .release),
                 graph: graph,
                 fileSystem: fs,
                 observabilityScope: observability.topScope
@@ -5131,7 +5136,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
         // Test debug configuration
         do {
             let result = try await BuildPlanResult(plan: mockBuildPlan(
-                environment: BuildEnvironment(platform: .macOS, configuration: .debug),
+                environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug),
                 graph: graph,
                 fileSystem: fs,
                 observabilityScope: observability.topScope
@@ -5162,7 +5167,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
         // Test release configuration
         do {
             let result = try await BuildPlanResult(plan: mockBuildPlan(
-                environment: BuildEnvironment(platform: .macOS, configuration: .release),
+                environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .release),
                 graph: graph,
                 fileSystem: fs,
                 observabilityScope: observability.topScope
@@ -7235,6 +7240,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
         let result = try await BuildPlanResult(plan: mockBuildPlan(
             environment: BuildEnvironment(
                 platform: .linux,
+                isHost: true,
                 configuration: .release
             ),
             graph: graph,
diff --git a/Tests/BuildTests/LLBuildManifestBuilderTests.swift b/Tests/BuildTests/LLBuildManifestBuilderTests.swift
index f2bf17e5663..dea4261abdc 100644
--- a/Tests/BuildTests/LLBuildManifestBuilderTests.swift
+++ b/Tests/BuildTests/LLBuildManifestBuilderTests.swift
@@ -56,6 +56,7 @@ struct LLBuildManifestBuilderTests {
         var plan = try await mockBuildPlan(
             environment: BuildEnvironment(
                 platform: .macOS,
+                isHost: true,
                 configuration: .release
             ),
             graph: graph,
@@ -86,6 +87,7 @@ struct LLBuildManifestBuilderTests {
         plan = try await mockBuildPlan(
             environment: BuildEnvironment(
                 platform: .macOS,
+                isHost: true,
                 configuration: .debug
             ),
             graph: graph,
@@ -129,6 +131,7 @@ struct LLBuildManifestBuilderTests {
         plan = try await mockBuildPlan(
             environment: BuildEnvironment(
                 platform: .linux,
+                isHost: true,
                 configuration: .release
             ),
             graph: graph,
@@ -155,6 +158,7 @@ struct LLBuildManifestBuilderTests {
         plan = try await mockBuildPlan(
             environment: BuildEnvironment(
                 platform: .linux,
+                isHost: true,
                 configuration: .debug
             ),
             graph: graph,
diff --git a/Tests/BuildTests/PluginInvocationTests.swift b/Tests/BuildTests/PluginInvocationTests.swift
index 7569ed86851..b49bbac7c60 100644
--- a/Tests/BuildTests/PluginInvocationTests.swift
+++ b/Tests/BuildTests/PluginInvocationTests.swift
@@ -233,7 +233,7 @@ final class PluginInvocationTests: XCTestCase {
         let pluginRunner = MockPluginScriptRunner()
         let buildParameters = mockBuildParameters(
             destination: .host,
-            environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+            environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
         )
 
         let results = try await invokeBuildToolPlugins(
@@ -960,7 +960,7 @@ final class PluginInvocationTests: XCTestCase {
                 let outputDir = packageDir.appending(".build")
                 let buildParameters = mockBuildParameters(
                     destination: .host,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
                 )
 
                 let result = try await invokeBuildToolPlugins(
@@ -1102,7 +1102,7 @@ final class PluginInvocationTests: XCTestCase {
                 let outputDir = packageDir.appending(".build")
                 let buildParameters = mockBuildParameters(
                     destination: .host,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
                 )
 
                 let result = try await invokeBuildToolPlugins(
@@ -1456,7 +1456,7 @@ final class PluginInvocationTests: XCTestCase {
             let outputDir = packageDir.appending(".build")
             let buildParameters = mockBuildParameters(
                 destination: .host,
-                environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+                environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
             )
 
             return try await invokeBuildToolPlugins(
diff --git a/Tests/BuildTests/ProductBuildDescriptionTests.swift b/Tests/BuildTests/ProductBuildDescriptionTests.swift
index 5674142e10d..d24e4962811 100644
--- a/Tests/BuildTests/ProductBuildDescriptionTests.swift
+++ b/Tests/BuildTests/ProductBuildDescriptionTests.swift
@@ -63,7 +63,7 @@ final class ProductBuildDescriptionTests: XCTestCase {
             package: package,
             product: product,
             toolsVersion: .v5_9,
-            buildParameters: mockBuildParameters(destination: .target, environment: .init(platform: .macOS)),
+            buildParameters: mockBuildParameters(destination: .target, environment: .init(platform: .macOS, isHost: true)),
             fileSystem: fs,
             observabilityScope: observability.topScope
         )
diff --git a/Tests/FunctionalTests/PluginTests.swift b/Tests/FunctionalTests/PluginTests.swift
index 03f4af842b8..5d35a77b6a8 100644
--- a/Tests/FunctionalTests/PluginTests.swift
+++ b/Tests/FunctionalTests/PluginTests.swift
@@ -806,7 +806,7 @@ final class PluginTests {
                     let success = try await withCheckedThrowingContinuation { continuation in
                       plugin.invoke(
                         action: .performCommand(package: package, arguments: arguments),
-                        buildEnvironment: BuildEnvironment(platform: .macOS, configuration: .debug),
+                        buildEnvironment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug),
                         scriptRunner: scriptRunner,
                         workingDirectory: package.path,
                         outputDirectory: pluginDir.appending("output"),
@@ -1101,7 +1101,7 @@ final class PluginTests {
                 try await withTaskCancellationHandler {
                     _ = try await plugin.invoke(
                         action: .performCommand(package: package, arguments: []),
-                        buildEnvironment: BuildEnvironment(platform: .macOS, configuration: .debug),
+                        buildEnvironment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug),
                         scriptRunner: scriptRunner,
                         workingDirectory: package.path,
                         outputDirectory: pluginDir.appending("output"),
diff --git a/Tests/PackageGraphTests/ModulesGraphTests.swift b/Tests/PackageGraphTests/ModulesGraphTests.swift
index 55699e5c739..2baf5bf092a 100644
--- a/Tests/PackageGraphTests/ModulesGraphTests.swift
+++ b/Tests/PackageGraphTests/ModulesGraphTests.swift
@@ -2369,20 +2369,20 @@ struct ModulesGraphTests {
             try result.checkTarget("Foo") { result in
                 result.check(dependencies: "Bar", "Baz", "Biz")
                 try result.checkDependency("Bar") { result in
-                    result.checkConditions(satisfy: .init(platform: .linux, configuration: .debug))
-                    result.checkConditions(satisfy: .init(platform: .linux, configuration: .release))
-                    result.checkConditions(dontSatisfy: .init(platform: .macOS, configuration: .release))
+                    result.checkConditions(satisfy: .init(platform: .linux, isHost: true, configuration: .debug))
+                    result.checkConditions(satisfy: .init(platform: .linux, isHost: true, configuration: .release))
+                    result.checkConditions(dontSatisfy: .init(platform: .macOS, isHost: true, configuration: .release))
                 }
                 try result.checkDependency("Baz") { result in
-                    result.checkConditions(satisfy: .init(platform: .watchOS, configuration: .debug))
-                    result.checkConditions(satisfy: .init(platform: .tvOS, configuration: .debug))
-                    result.checkConditions(dontSatisfy: .init(platform: .tvOS, configuration: .release))
+                    result.checkConditions(satisfy: .init(platform: .watchOS, isHost: true, configuration: .debug))
+                    result.checkConditions(satisfy: .init(platform: .tvOS, isHost: true, configuration: .debug))
+                    result.checkConditions(dontSatisfy: .init(platform: .tvOS, isHost: true, configuration: .release))
                 }
                 try result.checkDependency("Biz") { result in
-                    result.checkConditions(satisfy: .init(platform: .watchOS, configuration: .release))
-                    result.checkConditions(satisfy: .init(platform: .iOS, configuration: .release))
-                    result.checkConditions(dontSatisfy: .init(platform: .iOS, configuration: .debug))
-                    result.checkConditions(dontSatisfy: .init(platform: .macOS, configuration: .release))
+                    result.checkConditions(satisfy: .init(platform: .watchOS, isHost: true, configuration: .release))
+                    result.checkConditions(satisfy: .init(platform: .iOS, isHost: true, configuration: .release))
+                    result.checkConditions(dontSatisfy: .init(platform: .iOS, isHost: true, configuration: .debug))
+                    result.checkConditions(dontSatisfy: .init(platform: .macOS, isHost: true, configuration: .release))
                 }
             }
         }
diff --git a/Tests/PackageLoadingTests/PackageBuilderTests.swift b/Tests/PackageLoadingTests/PackageBuilderTests.swift
index c7c685ecab9..be41b4c31c7 100644
--- a/Tests/PackageLoadingTests/PackageBuilderTests.swift
+++ b/Tests/PackageLoadingTests/PackageBuilderTests.swift
@@ -2631,7 +2631,7 @@ struct PackageBuilderTests {
             try package.checkModule("cbar") { package in
                 let scope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
                 )
                 #expect(scope.evaluate(.GCC_PREPROCESSOR_DEFINITIONS) == ["CCC=2", "CXX"])
                 #expect(scope.evaluate(.HEADER_SEARCH_PATHS) == ["Sources/headers", "Sources/cppheaders"])
@@ -2640,7 +2640,7 @@ struct PackageBuilderTests {
 
                 let releaseScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .release)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .release)
                 )
                 #expect(releaseScope.evaluate(.GCC_PREPROCESSOR_DEFINITIONS) == ["CCC=2", "CXX", "RCXX"])
             }
@@ -2648,20 +2648,20 @@ struct PackageBuilderTests {
             try package.checkModule("bar") { package in
                 let scope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .linux, configuration: .debug)
+                    environment: BuildEnvironment(platform: .linux, isHost: true, configuration: .debug)
                 )
                 #expect(scope.evaluate(.SWIFT_ACTIVE_COMPILATION_CONDITIONS) == ["SOMETHING", "LINUX"])
                 #expect(scope.evaluate(.OTHER_SWIFT_FLAGS) == ["-Isfoo", "-L", "sbar"])
 
                 let rscope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .linux, configuration: .release)
+                    environment: BuildEnvironment(platform: .linux, isHost: true, configuration: .release)
                 )
                 #expect(rscope.evaluate(.SWIFT_ACTIVE_COMPILATION_CONDITIONS) == ["SOMETHING", "LINUX", "RLINUX"])
 
                 let mscope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
                 )
                 #expect(mscope.evaluate(.SWIFT_ACTIVE_COMPILATION_CONDITIONS) == ["SOMETHING", "DMACOS"])
             }
@@ -2669,7 +2669,7 @@ struct PackageBuilderTests {
             try package.checkModule("exe") { package in
                 let scope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .linux, configuration: .debug)
+                    environment: BuildEnvironment(platform: .linux, isHost: true, configuration: .debug)
                 )
                 #expect(scope.evaluate(.LINK_LIBRARIES) == ["sqlite3"])
                 #expect(scope.evaluate(.OTHER_LDFLAGS) == ["-Ilfoo", "-L", "lbar"])
@@ -2680,7 +2680,7 @@ struct PackageBuilderTests {
 
                 let mscope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .iOS, configuration: .debug)
+                    environment: BuildEnvironment(platform: .iOS, isHost: false, configuration: .debug)
                 )
                 #expect(mscope.evaluate(.LINK_LIBRARIES) == ["sqlite3"])
                 #expect(mscope.evaluate(.LINK_FRAMEWORKS) == ["CoreData"])
@@ -2728,7 +2728,7 @@ struct PackageBuilderTests {
             try package.checkModule("foo") { package in
                 let macosDebugScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
                 )
                 #expect(macosDebugScope.evaluate(.OTHER_CFLAGS) == [])
                 #expect(macosDebugScope.evaluate(.OTHER_CPLUSPLUSFLAGS) == [])
@@ -2736,7 +2736,7 @@ struct PackageBuilderTests {
 
                 let macosReleaseScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .release)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .release)
                 )
                 #expect(macosReleaseScope.evaluate(.OTHER_CFLAGS) == [])
                 #expect(macosReleaseScope.evaluate(.OTHER_CPLUSPLUSFLAGS) == [])
@@ -2746,21 +2746,21 @@ struct PackageBuilderTests {
             try package.checkModule("bar") { package in
                 let linuxDebugScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .linux, configuration: .debug)
+                    environment: BuildEnvironment(platform: .linux, isHost: true, configuration: .debug)
                 )
                 #expect(linuxDebugScope.evaluate(.OTHER_SWIFT_FLAGS) == [])
                 #expect(linuxDebugScope.evaluate(.OTHER_LDFLAGS) == [])
 
                 let linuxReleaseScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .linux, configuration: .release)
+                    environment: BuildEnvironment(platform: .linux, isHost: true, configuration: .release)
                 )
                 #expect(linuxReleaseScope.evaluate(.OTHER_SWIFT_FLAGS) == [])
                 #expect(linuxReleaseScope.evaluate(.OTHER_LDFLAGS) == [])
 
                 let macosDebugScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
                 )
                 #expect(macosDebugScope.evaluate(.OTHER_SWIFT_FLAGS) == [])
                 #expect(macosDebugScope.evaluate(.OTHER_LDFLAGS) == [])
@@ -2928,22 +2928,22 @@ struct PackageBuilderTests {
                 target.check(dependencies: ["Bar", "Baz", "Biz"])
 
                 target.checkDependency("Bar") { result in
-                    result.checkConditions(satisfy: .init(platform: .macOS, configuration: .debug))
-                    result.checkConditions(satisfy: .init(platform: .macOS, configuration: .release))
-                    result.checkConditions(dontSatisfy: .init(platform: .watchOS, configuration: .release))
+                    result.checkConditions(satisfy: .init(platform: .macOS, isHost: true, configuration: .debug))
+                    result.checkConditions(satisfy: .init(platform: .macOS, isHost: true, configuration: .release))
+                    result.checkConditions(dontSatisfy: .init(platform: .watchOS, isHost: false, configuration: .release))
                 }
 
                 target.checkDependency("Baz") { result in
-                    result.checkConditions(satisfy: .init(platform: .macOS, configuration: .debug))
-                    result.checkConditions(satisfy: .init(platform: .linux, configuration: .debug))
-                    result.checkConditions(dontSatisfy: .init(platform: .linux, configuration: .release))
+                    result.checkConditions(satisfy: .init(platform: .macOS, isHost: true, configuration: .debug))
+                    result.checkConditions(satisfy: .init(platform: .linux, isHost: true, configuration: .debug))
+                    result.checkConditions(dontSatisfy: .init(platform: .linux, isHost: true, configuration: .release))
                 }
 
                 target.checkDependency("Biz") { result in
-                    result.checkConditions(satisfy: .init(platform: .watchOS, configuration: .release))
-                    result.checkConditions(satisfy: .init(platform: .iOS, configuration: .release))
-                    result.checkConditions(dontSatisfy: .init(platform: .linux, configuration: .release))
-                    result.checkConditions(dontSatisfy: .init(platform: .iOS, configuration: .debug))
+                    result.checkConditions(satisfy: .init(platform: .watchOS, isHost: false, configuration: .release))
+                    result.checkConditions(satisfy: .init(platform: .iOS, isHost: false, configuration: .release))
+                    result.checkConditions(dontSatisfy: .init(platform: .linux, isHost: false, configuration: .release))
+                    result.checkConditions(dontSatisfy: .init(platform: .iOS, isHost: false, configuration: .debug))
                 }
             }
         }
@@ -3234,13 +3234,13 @@ struct PackageBuilderTests {
             try package.checkModule("foo") { package in
                 let macosDebugScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
                 )
                 #expect(macosDebugScope.evaluate(.SWIFT_VERSION) == ["5"])
 
                 let macosReleaseScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .release)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .release)
                 )
                 #expect(macosReleaseScope.evaluate(.SWIFT_VERSION) == ["5"])
             }
@@ -3248,19 +3248,19 @@ struct PackageBuilderTests {
             try package.checkModule("bar") { package in
                 let linuxDebugScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .linux, configuration: .debug)
+                    environment: BuildEnvironment(platform: .linux, isHost: true, configuration: .debug)
                 )
                 #expect(linuxDebugScope.evaluate(.SWIFT_VERSION) == ["3"])
 
                 let macosDebugScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
                 )
                 #expect(macosDebugScope.evaluate(.SWIFT_VERSION) == ["4"])
 
                 let macosReleaseScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .release)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .release)
                 )
                 #expect(macosReleaseScope.evaluate(.SWIFT_VERSION) == ["5"])
             }
@@ -3293,7 +3293,7 @@ struct PackageBuilderTests {
             try package.checkModule("foo") { package in
                 let macosDebugScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
                 )
                 #expect(
                     macosDebugScope.evaluate(.OTHER_SWIFT_FLAGS) ==
@@ -3302,7 +3302,7 @@ struct PackageBuilderTests {
 
                 let macosReleaseScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .release)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .release)
                 )
                 #expect(
                     macosReleaseScope.evaluate(.OTHER_SWIFT_FLAGS) ==
@@ -3339,7 +3339,7 @@ struct PackageBuilderTests {
             try package.checkModule("cfoo") { package in
                 let macosDebugScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
                 )
                 #expect(
                     macosDebugScope.evaluate(.OTHER_CFLAGS) ==
@@ -3348,7 +3348,7 @@ struct PackageBuilderTests {
 
                 let macosReleaseScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .release)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .release)
                 )
                 #expect(
                     macosReleaseScope.evaluate(.OTHER_CFLAGS) ==
@@ -3385,7 +3385,7 @@ struct PackageBuilderTests {
             try package.checkModule("cxxfoo") { package in
                 let macosDebugScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
                 )
                 #expect(
                     macosDebugScope.evaluate(.OTHER_CPLUSPLUSFLAGS) ==
@@ -3394,7 +3394,7 @@ struct PackageBuilderTests {
 
                 let macosReleaseScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .release)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .release)
                 )
                 #expect(
                     macosReleaseScope.evaluate(.OTHER_CPLUSPLUSFLAGS) ==
@@ -3429,7 +3429,7 @@ struct PackageBuilderTests {
             try package.checkModule("cfoo") { package in
                 let macosDebugScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
                 )
                 #expect(
                     macosDebugScope.evaluate(.OTHER_CFLAGS) ==
@@ -3438,7 +3438,7 @@ struct PackageBuilderTests {
 
                 let macosReleaseScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .release)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .release)
                 )
                 #expect(
                     macosReleaseScope.evaluate(.OTHER_CFLAGS) ==
@@ -3473,7 +3473,7 @@ struct PackageBuilderTests {
             try package.checkModule("cxxfoo") { package in
                 let macosDebugScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
                 )
                 #expect(
                     macosDebugScope.evaluate(.OTHER_CPLUSPLUSFLAGS) ==
@@ -3482,7 +3482,7 @@ struct PackageBuilderTests {
 
                 let macosReleaseScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .release)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .release)
                 )
                 #expect(
                     macosReleaseScope.evaluate(.OTHER_CPLUSPLUSFLAGS) ==
@@ -3523,14 +3523,14 @@ struct PackageBuilderTests {
             try package.checkModule("A") { package in
                 let macosDebugScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
                 )
                 #expect(macosDebugScope.evaluate(.OTHER_SWIFT_FLAGS).contains("-default-isolation"))
                 #expect(macosDebugScope.evaluate(.OTHER_SWIFT_FLAGS).contains("MainActor"))
 
                 let macosReleaseScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .release)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .release)
                 )
                 #expect(macosReleaseScope.evaluate(.OTHER_SWIFT_FLAGS).contains("-default-isolation"))
                 #expect(macosReleaseScope.evaluate(.OTHER_SWIFT_FLAGS).contains("MainActor"))
@@ -3540,21 +3540,21 @@ struct PackageBuilderTests {
             try package.checkModule("B") { package in
                 let linuxDebugScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .linux, configuration: .debug)
+                    environment: BuildEnvironment(platform: .linux, isHost: true, configuration: .debug)
                 )
                 #expect(linuxDebugScope.evaluate(.OTHER_SWIFT_FLAGS).contains("-default-isolation"))
                 #expect(linuxDebugScope.evaluate(.OTHER_SWIFT_FLAGS).contains("nonisolated"))
 
                 let macosDebugScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .debug)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .debug)
                 )
                 #expect(macosDebugScope.evaluate(.OTHER_SWIFT_FLAGS).contains("-default-isolation"))
                 #expect(macosDebugScope.evaluate(.OTHER_SWIFT_FLAGS).contains("MainActor"))
 
                 let macosReleaseScope = BuildSettings.Scope(
                     package.target.buildSettings,
-                    environment: BuildEnvironment(platform: .macOS, configuration: .release)
+                    environment: BuildEnvironment(platform: .macOS, isHost: true, configuration: .release)
                 )
                 #expect(!macosReleaseScope.evaluate(.OTHER_SWIFT_FLAGS).contains("-default-isolation") ||
                         !macosReleaseScope.evaluate(.OTHER_SWIFT_FLAGS).contains("MainActor"))
diff --git a/Tests/SPMBuildCoreTests/BuildParametersTests.swift b/Tests/SPMBuildCoreTests/BuildParametersTests.swift
index cf79703fe9b..51d4f40eb30 100644
--- a/Tests/SPMBuildCoreTests/BuildParametersTests.swift
+++ b/Tests/SPMBuildCoreTests/BuildParametersTests.swift
@@ -21,7 +21,7 @@ struct BuildParametersTests {
     func configurationDependentProperties() throws {
         var parameters = mockBuildParameters(
             destination: .host,
-            environment: BuildEnvironment(platform: .linux, configuration: .debug)
+            environment: BuildEnvironment(platform: .linux, isHost: true, configuration: .debug)
         )
         #expect(parameters.enableTestability)
         parameters.configuration = .release
diff --git a/Tests/WorkspaceTests/PrebuiltsTests.swift b/Tests/WorkspaceTests/PrebuiltsTests.swift
index 759e94c3721..c701b1f9573 100644
--- a/Tests/WorkspaceTests/PrebuiltsTests.swift
+++ b/Tests/WorkspaceTests/PrebuiltsTests.swift
@@ -26,6 +26,8 @@ import _InternalTestSupport
 
 final class PrebuiltsTests: XCTestCase {
     let swiftVersion = "\(SwiftVersion.current.major).\(SwiftVersion.current.minor)"
+    let host = BuildEnvironment(platform: .macOS, isHost: true)
+    let dest = BuildEnvironment(platform: .linux, isHost: false)
 
     func with(
         fileSystem: FileSystem,
@@ -96,11 +98,19 @@ final class PrebuiltsTests: XCTestCase {
             let rootPackage = try MockPackage(
                 name: "Foo",
                 targets: [
+                    MockTarget(
+                        name: "SwiftSyntaxExtras",
+                        dependencies: [
+                            .product(name: "SwiftSyntaxMacros", package: "swift-syntax"),
+                            .product(name: "SwiftCompilerPlugin", package: "swift-syntax"),
+                        ]
+                    ),
                     MockTarget(
                         name: "FooMacros",
                         dependencies: [
                             .product(name: "SwiftSyntaxMacros", package: "swift-syntax"),
                             .product(name: "SwiftCompilerPlugin", package: "swift-syntax"),
+                            "SwiftSyntaxExtras",
                         ],
                         type: .macro
                     ),
@@ -113,6 +123,13 @@ final class PrebuiltsTests: XCTestCase {
                         dependencies: ["Foo"],
                         type: .executable
                     ),
+                    MockTarget(
+                        name: "ExtrasClient",
+                        dependencies: [
+                            "SwiftSyntaxExtras",
+                        ],
+                        type: .executable
+                    ),
                     MockTarget(
                         name: "FooTests",
                         dependencies: [
@@ -150,17 +167,37 @@ final class PrebuiltsTests: XCTestCase {
         }
     }
 
-    func checkSettings(_ rootPackage: ResolvedPackage, _ targetName: String, usePrebuilt: Bool) throws {
-        let target = try XCTUnwrap(rootPackage.underlying.modules.first(where: { $0.name == targetName }))
+    func checkSettings(_ rootPackage: ResolvedPackage, _ targetName: String, env: BuildEnvironment, usePrebuilt: Bool) throws {
+        let target = try XCTUnwrap(rootPackage.modules[ResolvedModule.ID(moduleName: targetName, packageIdentity: rootPackage.identity)])
+
+        let swiftFlags = (target.underlying.buildSettings.assignments[.OTHER_SWIFT_FLAGS] ?? []).filter({
+            $0.conditions.allSatisfy({ $0.satisfies(env) })
+        }).flatMap({ $0.values })
+
+        let ldFlags = (target.underlying.buildSettings.assignments[.OTHER_LDFLAGS] ?? []).filter({
+            $0.conditions.allSatisfy({ $0.satisfies(env) })
+        }).flatMap({ $0.values })
+
+        let deps = target.dependencies.filter({ $0.conditions.allSatisfy({ $0.satisfies(env) })})
+        let ssDeps = deps.filter({
+            guard case .product(let product, conditions: _) = $0 else {
+                return false
+            }
+            return product.packageIdentity == .plain("swift-syntax")
+        })
+
         if usePrebuilt {
-            let swiftFlags = try XCTUnwrap(target.buildSettings.assignments[.OTHER_SWIFT_FLAGS]).flatMap({ $0.values })
             XCTAssertTrue(swiftFlags.contains("-I/tmp/ws/.build/prebuilts/swift-syntax/600.0.1/\(self.swiftVersion)-MacroSupport-macos_aarch64/Modules".fixwin))
             XCTAssertTrue(swiftFlags.contains("-I/tmp/ws/.build/prebuilts/swift-syntax/600.0.1/\(self.swiftVersion)-MacroSupport-macos_aarch64/include/_SwiftSyntaxCShims".fixwin))
-            let ldFlags = try XCTUnwrap(target.buildSettings.assignments[.OTHER_LDFLAGS]).flatMap({ $0.values })
+
             XCTAssertTrue(ldFlags.contains("/tmp/ws/.build/prebuilts/swift-syntax/600.0.1/\(self.swiftVersion)-MacroSupport-macos_aarch64/lib/libMacroSupport.a".fixwin))
+
+            XCTAssertTrue(ssDeps.isEmpty)
         } else {
-            XCTAssertNil(target.buildSettings.assignments[.OTHER_SWIFT_FLAGS])
-            XCTAssertNil(target.buildSettings.assignments[.OTHER_LDFLAGS])
+            XCTAssertTrue(swiftFlags.isEmpty)
+            XCTAssertTrue(ldFlags.isEmpty)
+
+            XCTAssertFalse(ssDeps.isEmpty)
         }
     }
 
@@ -216,10 +253,10 @@ final class PrebuiltsTests: XCTestCase {
             try await workspace.checkPackageGraph(roots: ["Foo"]) { modulesGraph, diagnostics in
                 XCTAssertTrue(diagnostics.filter({ $0.severity == .error || $0.severity == .warning }).isEmpty)
                 let rootPackage = try XCTUnwrap(modulesGraph.rootPackages.first)
-                try checkSettings(rootPackage, "FooMacros", usePrebuilt: true)
-                try checkSettings(rootPackage, "FooTests", usePrebuilt: true)
-                try checkSettings(rootPackage, "Foo", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooClient", usePrebuilt: false)
+                try checkSettings(rootPackage, "FooMacros", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "FooTests", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: dest, usePrebuilt: false)
             }
         }
     }
@@ -280,10 +317,10 @@ final class PrebuiltsTests: XCTestCase {
             try await workspace.checkPackageGraph(roots: [rootPackage.name]) { modulesGraph, diagnostics in
                 XCTAssertTrue(diagnostics.filter({ $0.severity == .error || $0.severity == .warning }).isEmpty)
                 let rootPackage = try XCTUnwrap(modulesGraph.rootPackages.first)
-                try checkSettings(rootPackage, "FooMacros", usePrebuilt: true)
-                try checkSettings(rootPackage, "FooTests", usePrebuilt: true)
-                try checkSettings(rootPackage, "Foo", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooClient", usePrebuilt: false)
+                try checkSettings(rootPackage, "FooMacros", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "FooTests", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: dest, usePrebuilt: false)
             }
 
             // Change the version of swift syntax to one that doesn't have prebuilts
@@ -310,10 +347,10 @@ final class PrebuiltsTests: XCTestCase {
             try await workspace.checkPackageGraph(roots: [rootPackage.name]) { modulesGraph, diagnostics in
                 XCTAssertTrue(diagnostics.filter({ $0.severity == .error || $0.severity == .warning }).isEmpty)
                 let rootPackage = try XCTUnwrap(modulesGraph.rootPackages.first)
-                try checkSettings(rootPackage, "FooMacros", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooTests", usePrebuilt: false)
-                try checkSettings(rootPackage, "Foo", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooClient", usePrebuilt: false)
+                try checkSettings(rootPackage, "FooMacros", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "FooTests", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: dest, usePrebuilt: false)
             }
 
             // Change it back
@@ -323,10 +360,10 @@ final class PrebuiltsTests: XCTestCase {
             try await workspace.checkPackageGraph(roots: [rootPackage.name]) { modulesGraph, diagnostics in
                 XCTAssertTrue(diagnostics.filter({ $0.severity == .error || $0.severity == .warning }).isEmpty)
                 let rootPackage = try XCTUnwrap(modulesGraph.rootPackages.first)
-                try checkSettings(rootPackage, "FooMacros", usePrebuilt: true)
-                try checkSettings(rootPackage, "FooTests", usePrebuilt: true)
-                try checkSettings(rootPackage, "Foo", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooClient", usePrebuilt: false)
+                try checkSettings(rootPackage, "FooMacros", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "FooTests", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: dest, usePrebuilt: false)
             }
         }
     }
@@ -385,10 +422,10 @@ final class PrebuiltsTests: XCTestCase {
             try await workspace.checkPackageGraph(roots: ["Foo"]) { modulesGraph, diagnostics in
                 XCTAssertTrue(diagnostics.filter({ $0.severity == .error }).isEmpty)
                 let rootPackage = try XCTUnwrap(modulesGraph.rootPackages.first)
-                try checkSettings(rootPackage, "FooMacros", usePrebuilt: true)
-                try checkSettings(rootPackage, "FooTests", usePrebuilt: true)
-                try checkSettings(rootPackage, "Foo", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooClient", usePrebuilt: false)
+                try checkSettings(rootPackage, "FooMacros", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "FooTests", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: dest, usePrebuilt: false)
             }
         }
     }
@@ -447,10 +484,10 @@ final class PrebuiltsTests: XCTestCase {
             try await workspace.checkPackageGraph(roots: ["Foo"]) { modulesGraph, diagnostics in
                 XCTAssertTrue(diagnostics.filter({ $0.severity == .error }).isEmpty)
                 let rootPackage = try XCTUnwrap(modulesGraph.rootPackages.first)
-                try checkSettings(rootPackage, "FooMacros", usePrebuilt: true)
-                try checkSettings(rootPackage, "FooTests", usePrebuilt: true)
-                try checkSettings(rootPackage, "Foo", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooClient", usePrebuilt: false)
+                try checkSettings(rootPackage, "FooMacros", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "FooTests", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: dest, usePrebuilt: false)
             }
         }
     }
@@ -509,10 +546,10 @@ final class PrebuiltsTests: XCTestCase {
             try await workspace.checkPackageGraph(roots: ["Foo"]) { modulesGraph, diagnostics in
                 XCTAssertTrue(diagnostics.filter({ $0.severity == .error }).isEmpty)
                 let rootPackage = try XCTUnwrap(modulesGraph.rootPackages.first)
-                try checkSettings(rootPackage, "FooMacros", usePrebuilt: true)
-                try checkSettings(rootPackage, "FooTests", usePrebuilt: true)
-                try checkSettings(rootPackage, "Foo", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooClient", usePrebuilt: false)
+                try checkSettings(rootPackage, "FooMacros", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "FooTests", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: dest, usePrebuilt: false)
             }
         }
     }
@@ -561,10 +598,10 @@ final class PrebuiltsTests: XCTestCase {
             try await workspace.checkPackageGraph(roots: ["Foo"]) { modulesGraph, diagnostics in
                 XCTAssertTrue(diagnostics.filter({ $0.severity == .error }).isEmpty)
                 let rootPackage = try XCTUnwrap(modulesGraph.rootPackages.first)
-                try checkSettings(rootPackage, "FooMacros", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooTests", usePrebuilt: false)
-                try checkSettings(rootPackage, "Foo", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooClient", usePrebuilt: false)
+                try checkSettings(rootPackage, "FooMacros", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "FooTests", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: dest, usePrebuilt: false)
             }
             
             await secondFetch.set(true)
@@ -572,10 +609,10 @@ final class PrebuiltsTests: XCTestCase {
             try await workspace.checkPackageGraph(roots: ["Foo"]) { modulesGraph, diagnostics in
                 XCTAssertTrue(diagnostics.filter({ $0.severity == .error }).isEmpty)
                 let rootPackage = try XCTUnwrap(modulesGraph.rootPackages.first)
-                try checkSettings(rootPackage, "FooMacros", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooTests", usePrebuilt: false)
-                try checkSettings(rootPackage, "Foo", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooClient", usePrebuilt: false)
+                try checkSettings(rootPackage, "FooMacros", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "FooTests", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: dest, usePrebuilt: false)
             }
         }
     }
@@ -628,10 +665,10 @@ final class PrebuiltsTests: XCTestCase {
             try await workspace.checkPackageGraph(roots: ["Foo"]) { modulesGraph, diagnostics in
                 XCTAssertTrue(diagnostics.filter({ $0.severity == .error }).isEmpty)
                 let rootPackage = try XCTUnwrap(modulesGraph.rootPackages.first)
-                try checkSettings(rootPackage, "FooMacros", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooTests", usePrebuilt: false)
-                try checkSettings(rootPackage, "Foo", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooClient", usePrebuilt: false)
+                try checkSettings(rootPackage, "FooMacros", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "FooTests", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: dest, usePrebuilt: false)
             }
         }
     }
@@ -677,10 +714,10 @@ final class PrebuiltsTests: XCTestCase {
             try await workspace.checkPackageGraph(roots: ["Foo"]) { modulesGraph, diagnostics in
                 XCTAssertTrue(diagnostics.filter({ $0.severity == .error }).isEmpty)
                 let rootPackage = try XCTUnwrap(modulesGraph.rootPackages.first)
-                try checkSettings(rootPackage, "FooMacros", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooTests", usePrebuilt: false)
-                try checkSettings(rootPackage, "Foo", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooClient", usePrebuilt: false)
+                try checkSettings(rootPackage, "FooMacros", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "FooTests", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: dest, usePrebuilt: false)
             }
         }
     }
@@ -748,10 +785,10 @@ final class PrebuiltsTests: XCTestCase {
                 XCTAssertTrue(diagnostics.filter({ $0.severity == .error }).isEmpty)
                 XCTAssertTrue(diagnostics.contains(where: { $0.message == "Failed to decode prebuilt manifest: invalidSignature" }))
                 let rootPackage = try XCTUnwrap(modulesGraph.rootPackages.first)
-                try checkSettings(rootPackage, "FooMacros", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooTests", usePrebuilt: false)
-                try checkSettings(rootPackage, "Foo", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooClient", usePrebuilt: false)
+                try checkSettings(rootPackage, "FooMacros", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "FooTests", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: dest, usePrebuilt: false)
             }
         }
     }
@@ -809,10 +846,10 @@ final class PrebuiltsTests: XCTestCase {
             try await workspace.checkPackageGraph(roots: ["Foo"]) { modulesGraph, diagnostics in
                 XCTAssertTrue(diagnostics.filter({ $0.severity == .error }).isEmpty)
                 let rootPackage = try XCTUnwrap(modulesGraph.rootPackages.first)
-                try checkSettings(rootPackage, "FooMacros", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooTests", usePrebuilt: false)
-                try checkSettings(rootPackage, "Foo", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooClient", usePrebuilt: false)
+                try checkSettings(rootPackage, "FooMacros", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "FooTests", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: dest, usePrebuilt: false)
             }
         }
     }
@@ -873,10 +910,10 @@ final class PrebuiltsTests: XCTestCase {
             try await workspace.checkPackageGraph(roots: ["Foo"]) { modulesGraph, diagnostics in
                 XCTAssertTrue(diagnostics.filter({ $0.severity == .error }).isEmpty)
                 let rootPackage = try XCTUnwrap(modulesGraph.rootPackages.first)
-                try checkSettings(rootPackage, "FooMacros", usePrebuilt: true)
-                try checkSettings(rootPackage, "FooTests", usePrebuilt: true)
-                try checkSettings(rootPackage, "Foo", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooClient", usePrebuilt: false)
+                try checkSettings(rootPackage, "FooMacros", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "FooTests", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: host, usePrebuilt: true)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: dest, usePrebuilt: false)
             }
         }
     }
@@ -928,10 +965,10 @@ final class PrebuiltsTests: XCTestCase {
             try await workspace.checkPackageGraph(roots: ["Foo"]) { modulesGraph, diagnostics in
                 XCTAssertTrue(diagnostics.filter({ $0.severity == .error }).isEmpty)
                 let rootPackage = try XCTUnwrap(modulesGraph.rootPackages.first)
-                try checkSettings(rootPackage, "FooMacros", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooTests", usePrebuilt: false)
-                try checkSettings(rootPackage, "Foo", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooClient", usePrebuilt: false)
+                try checkSettings(rootPackage, "FooMacros", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "FooTests", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: dest, usePrebuilt: false)
             }
         }
     }
@@ -956,10 +993,10 @@ final class PrebuiltsTests: XCTestCase {
             try await workspace.checkPackageGraph(roots: ["Foo"]) { modulesGraph, diagnostics in
                 XCTAssertTrue(diagnostics.filter({ $0.severity == .error }).isEmpty)
                 let rootPackage = try XCTUnwrap(modulesGraph.rootPackages.first)
-                try checkSettings(rootPackage, "FooMacros", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooTests", usePrebuilt: false)
-                try checkSettings(rootPackage, "Foo", usePrebuilt: false)
-                try checkSettings(rootPackage, "FooClient", usePrebuilt: false)
+                try checkSettings(rootPackage, "FooMacros", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "FooTests", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: host, usePrebuilt: false)
+                try checkSettings(rootPackage, "SwiftSyntaxExtras", env: dest, usePrebuilt: false)
             }
         }
     }