Added support to TSC for using Netrc credentials for binary artifact access https://forums.swift.org/t/spm-support-basic-auth-for-non-git-binary-dependency-hosts/37878

Author: sstadelman

Package.swift

@@ -20,7 +20,7 @@ let macOSPlatform: SupportedPlatform
 if let deploymentTarget = ProcessInfo.processInfo.environment["SWIFTPM_MACOS_DEPLOYMENT_TARGET"] {
     macOSPlatform = .macOS(deploymentTarget)
 } else {
-    macOSPlatform = .macOS(.v10_13)
+    macOSPlatform = .macOS(.v10_10)
 }
 
 let package = Package(

Sources/Workspace/Workspace.swift

@@ -1404,9 +1404,15 @@ extension Workspace {
     private func download(_ artifacts: [ManagedArtifact], diagnostics: DiagnosticsEngine) {
         let group = DispatchGroup()
         let tempDiagnostics = DiagnosticsEngine()
-
-        let netrc = try? Netrc.load(fromFileAtPath: netrcFilePath).get()
 
+        var authProvider: AuthorizationProviding? = nil
+        #if os(macOS)
+        // Netrc feature currently only supported on macOS 10.13+ due to dependency
+        // on NSTextCheckingResult.range(with:)
+        if #available(macOS 10.13, *) {
+            authProvider = try? Netrc.load(fromFileAtPath: netrcFilePath).get()
+        }
+        #endif
         for artifact in artifacts {
             group.enter()
 
@@ -1430,7 +1436,7 @@ extension Workspace {
             downloader.downloadFile(
                 at: parsedURL,
                 to: archivePath,
-                withAuthorizationProvider: netrc,
+                withAuthorizationProvider: authProvider,
                 progress: { bytesDownloaded, totalBytesToDownload in
                     self.delegate?.downloadingBinaryArtifact(
                         from: url,

Tests/CommandsTests/PackageToolTests.swift

@@ -43,7 +43,25 @@ final class PackageToolTests: XCTestCase {
     }
 
     func testNetrcFile() throws {
-        XCTAssert(try execute(["--netrc-file", "/Users/me/.hidden/.netrc"]).stdout.contains("Absolute path to netrc file"))
+        func verifyUnsupportedOSThrows() {
+            do {
+                // should throw and be caught
+                try execute(["--netrc-file", "/Users/me/.hidden/.netrc"])
+                XCTFail()
+            } catch {
+                XCTAssert(true)
+            }
+        }
+        #if os(macOS)
+        if #available(macOS 10.13, *) {
+            // should succeed
+            XCTAssert(try execute(["--netrc-file", "/Users/me/.hidden/.netrc"]).stdout.contains("Absolute path to netrc file"))
+        } else {
+            verifyUnsupportedOSThrows()
+        }
+        #else
+            verifyUnsupportedOSThrows()
+        #endif
     }
 
     func testResolve() throws {

swift-tools-support-core/Package.swift

@@ -15,6 +15,7 @@ import PackageDescription
 
 let package = Package(
     name: "swift-tools-support-core",
+    platforms: [.macOS(.v10_13)],
     products: [
         .library(
             name: "SwiftToolsSupport",