error: type 'Package.Dependency' has no member 'Package'

[runwuxiwusheng1992]

swift package generate-xcodeproj
/Users/haojia/PerfectTemplate: error: manifest parse error(s):
/Users/haojia/PerfectTemplate/Package.swift:12:10: error: type 'Package.Dependency' has no member 'Package'
.Package(url:"https://github.com/PerfectlySoft/Perfect-Session-MySQL.git", majorVersion: 0, minor: 0)