swift - 依赖图无法解析；发现这些相互矛盾的要求：

Question

我正在尝试导入此依赖项： https ://github.com/PureSwift/CFreeType

但我收到此错误：

Fetching https://github.com/PureSwift/CFreeType.git
error: dependency graph is unresolvable; found these conflicting requirements:

Dependencies: 
    https://github.com/PureSwift/CFreeType.git @ 1.0.4

该 repo 有一个 1.0.4 标签。难道我做错了什么？

这是我的 Package.swift：

// swift-tools-version:4.2
// The swift-tools-version declares the minimum version of Swift required to build this package.

import PackageDescription

let package = Package(
    name: "SwiftPlot",
    products: [
       // Products define the executables and libraries produced by a package, and make them visible to other packages.
       .library(
       name: "SwiftPlot",
       targets: ["AGG", "lodepng", "CPPAGGRenderer", "CAGGRenderer", "SwiftPlot", "SVGRenderer", "AGGRenderer"]),
    ],
    dependencies: [
        .package(url:"https://github.com/PureSwift/CFreeType.git", .exact("1.0.4")),
    ],
    targets: [
        //relevant targets
    ],
    cxxLanguageStandard: .cxx11
)