我想编写一个小的命令行工具作为一个快速包，但可执行。在开始时，我做了一个包与以下命令。

swift package init

现在，当我完成我的工作后，我意识到，这个命令确实创建了一个库，而不是一个可执行文件。现在我的问题是：有没有一种方法可以在Package.swift清单的帮助下改变这一点？
我已经尝试将Package.swift更改为可执行文件：

import PackageDescription

let package = Package(
    name: "lookupTool",
    products: [
        // Products define the executables and libraries a package produces, and make them visible to other packages.
        .executable( // <---- Here changed to executable
            name: "lookupTool",
            targets: ["lookupTool"]),
    ],
    dependencies: [
        // Dependencies declare other packages that this package depends on.
        // .package(url: /* package url */, from: "1.0.0"),
    ],
    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 this package depends on.
        .executableTarget( // <---- Here to executableTarget
            name: "lookupTool",
            dependencies: [],
                exclude: ["test.txt", "test2.txt", "test3.txt"]),
        .testTarget(
            name: "lookupToolTests",
            dependencies: ["lookupTool"]),
    ]
)

但它不起作用。
我无法将lookupTool作为可执行文件在可执行文件所在的./build/debug文件夹中运行。如果我键入命令ls，可执行文件就在那里。