Merge pull request #235 from apple/eng/conditionalize-deployment-target

Default to macOS 10.10 minimum deployment target again but allow it to be overridden

Author: shahmishal

Package.swift

@@ -14,10 +14,17 @@
 import PackageDescription
 import class Foundation.ProcessInfo
 
+let macOSPlatform: SupportedPlatform
+if let deploymentTarget = ProcessInfo.processInfo.environment["SWIFTTSC_MACOS_DEPLOYMENT_TARGET"] {
+    macOSPlatform = .macOS(deploymentTarget)
+} else {
+    macOSPlatform = .macOS(.v10_10)
+}
+
 let package = Package(
     name: "swift-tools-support-core",
     platforms: [
-        .macOS(.v10_15),
+        macOSPlatform,
         .iOS(.v13)
     ],
     products: [