現象 BuildTools/Package.swiftがこうで、 // swift-tools-version:5.1 import PackageDescription let package = Package( name: "BuildTools", platforms: [.macOS(.v10_11)], dependencies: [ .package(url: "https://github.com/nicklockwood/SwiftFormat", from: "0.49.0"), .package(url: "https://github.com/uber/mockolo.…