Use Combine instead of OpenCombine where possible

Package.swift

@@ -1,8 +1,14 @@
-// swift-tools-version:5.2
+// swift-tools-version:5.3
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
 
+let openCombineProduct: Target.Dependency = .product(
+  name: "OpenCombine",
+  package: "OpenCombine",
+  condition: .when(platforms: [.linux])
+)
+
 let package = Package(
   name: "carton",
   platforms: [.macOS(.v10_15)],
@@ -31,7 +37,7 @@ let package = Package(
         .product(name: "SwiftToolsSupport-auto", package: "swift-tools-support-core"),
         .product(name: "Vapor", package: "vapor"),
         "CartonHelpers",
-        "OpenCombine",
+        openCombineProduct,
         "SwiftToolchain",
       ]
     ),
@@ -41,15 +47,15 @@ let package = Package(
         .product(name: "AsyncHTTPClient", package: "async-http-client"),
         .product(name: "SwiftToolsSupport-auto", package: "swift-tools-support-core"),
         "CartonHelpers",
-        "OpenCombine",
+        openCombineProduct,
       ]
     ),
     .target(
       name: "CartonHelpers",
       dependencies: [
         .product(name: "AsyncHTTPClient", package: "async-http-client"),
         .product(name: "SwiftToolsSupport-auto", package: "swift-tools-support-core"),
-        "OpenCombine",
+        openCombineProduct,
       ]
     ),
     // This target is used only for release automation tasks and

Package@swift-5.2.swift

@@ -0,0 +1,70 @@
+// swift-tools-version:5.2
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+  name: "carton",
+  platforms: [.macOS(.v10_15)],
+  dependencies: [
+    .package(url: "https://github.com/swift-server/async-http-client.git", from: "1.1.1"),
+    .package(
+      url: "https://github.com/apple/swift-argument-parser",
+      .upToNextMinor(from: "0.2.0")
+    ),
+    .package(
+      url: "https://github.com/apple/swift-tools-support-core.git",
+      .upToNextMinor(from: "0.1.3")
+    ),
+    .package(url: "https://github.com/OpenCombine/OpenCombine.git", from: "0.10.0"),
+    .package(url: "https://github.com/vapor/vapor.git", .upToNextMinor(from: "4.5.0")),
+  ],
+  targets: [
+    // Targets are the basic building blocks of a package. A target can define a module
+    // or a test suite. Targets can depend on other targets in this package, and on
+    // products in packages which this package depends on.
+    .target(
+      name: "carton",
+      dependencies: [
+        .product(name: "ArgumentParser", package: "swift-argument-parser"),
+        .product(name: "AsyncHTTPClient", package: "async-http-client"),
+        .product(name: "SwiftToolsSupport-auto", package: "swift-tools-support-core"),
+        .product(name: "Vapor", package: "vapor"),
+        "CartonHelpers",
+        "OpenCombine",
+        "SwiftToolchain",
+      ]
+    ),
+    .target(
+      name: "SwiftToolchain",
+      dependencies: [
+        .product(name: "AsyncHTTPClient", package: "async-http-client"),
+        .product(name: "SwiftToolsSupport-auto", package: "swift-tools-support-core"),
+        "CartonHelpers",
+        "OpenCombine",
+      ]
+    ),
+    .target(
+      name: "CartonHelpers",
+      dependencies: [
+        .product(name: "AsyncHTTPClient", package: "async-http-client"),
+        .product(name: "SwiftToolsSupport-auto", package: "swift-tools-support-core"),
+        "OpenCombine",
+      ]
+    ),
+    // This target is used only for release automation tasks and
+    // should not be installed by `carton` users.
+    .target(
+      name: "carton-release",
+      dependencies: [
+        .product(name: "ArgumentParser", package: "swift-argument-parser"),
+        .product(name: "AsyncHTTPClient", package: "async-http-client"),
+        .product(name: "SwiftToolsSupport-auto", package: "swift-tools-support-core"),
+      ]
+    ),
+    .testTarget(
+      name: "CartonTests",
+      dependencies: ["carton"]
+    ),
+  ]
+)

Sources/CartonHelpers/ProcessRunner.swift

@@ -14,7 +14,11 @@
 
 import Dispatch
 import Foundation
+#if canImport(Combine)
+import Combine
+#else
 import OpenCombine
+#endif
 import TSCBasic
 
 struct ProcessRunnerError: Error, CustomStringConvertible {

Sources/SwiftToolchain/ProgressAnimation.swift

@@ -12,7 +12,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#if canImport(Combine)
+import Combine
+#else
 import OpenCombine
+#endif
 import TSCBasic
 import TSCUtility
 

Sources/SwiftToolchain/ToolchainManagement.swift

@@ -15,7 +15,11 @@
 import AsyncHTTPClient
 import CartonHelpers
 import Foundation
+#if canImport(Combine)
+import Combine
+#else
 import OpenCombine
+#endif
 import TSCBasic
 import TSCUtility
 

Sources/carton/Combine/Watcher.swift

@@ -12,7 +12,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#if canImport(Combine)
+import Combine
+#else
 import OpenCombine
+#endif
 import TSCBasic
 import TSCUtility
 

Sources/carton/Commands/Dev.swift

@@ -14,7 +14,11 @@
 
 import ArgumentParser
 import Foundation
+#if canImport(Combine)
+import Combine
+#else
 import OpenCombine
+#endif
 import SwiftToolchain
 import TSCBasic
 

Sources/carton/Commands/Test.swift

@@ -13,7 +13,11 @@
 // limitations under the License.
 
 import ArgumentParser
+#if canImport(Combine)
+import Combine
+#else
 import OpenCombine
+#endif
 import TSCBasic
 
 private let dependency = Dependency(

Sources/carton/Server/Server.swift

@@ -13,7 +13,11 @@
 // limitations under the License.
 
 import CartonHelpers
+#if canImport(Combine)
+import Combine
+#else
 import OpenCombine
+#endif
 import TSCBasic
 import Vapor