Merge pull request #557 from ahoppen/pr/no-docc-if-local-dependencies

Use SWIFTCI_USE_LOCAL_DEPS to check whether to clone swift-docc-plugin

Author: ahoppen

Package.swift

@@ -142,6 +142,9 @@ let package = Package(
   ]
 )
 
-if ProcessInfo.processInfo.environment["SWIFT_BUILD_SCRIPT_ENVIRONMENT"] == nil {
+// If `SWIFTCI_USE_LOCAL_DEPS` is set, we are in a CI enviornment that might disallow 
+// internet access, so we can't load swift-docc-plugin. Simply don't load it in these
+// environments because we don't build docc in CI at the moment.
+if ProcessInfo.processInfo.environment["SWIFTCI_USE_LOCAL_DEPS"] == nil {
     package.dependencies.append(.package(url: "https://github.com/apple/swift-docc-plugin", from: "1.0.0"))
 }