Example of Package.swift with environment variables support

Package.swift

// swift-tools-version:4.0
import PackageDescription

#if os(Linux)
import Glibc
#else
import Darwin.C
#endif

enum Enviroment: String {
	static let `default`: Enviroment = .development

	case development, production
	
	static func get() -> Enviroment {
		if let envPointer = getenv("ENV_TYPE") {
			let env = String(cString: envPointer)
			return Enviroment(rawValue: env) ?? .default
		} else {
			return .default
		}
	}
}

var dependencies: [Package.Dependency] = [
	.package(url: "https://github.com/vapor/vapor.git", from: "3.1.0"),
	.package(url: "https://github.com/Sorix/whirr-feedback-api-model", .branch("develop"))
]

var appTargetDependencies: [Target.Dependency] = ["Vapor", "FluentSQLite", "APIModel", "GooglePlaces"]

switch Enviroment.get() {
case .production:
	dependencies.append(.package(url: "https://github.com/vapor/fluent-postgresql.git", from: "1.0.0"))
	appTargetDependencies.append("FluentPostgreSQL")
case .development:
	dependencies.append(.package(url: "https://github.com/vapor/fluent-sqlite.git", from: "3.0.0"))
	appTargetDependencies.append("FluentSQLite")
}

let package = Package(
    name: "backend",
    dependencies: dependencies,
    targets: [
        .target(name: "GooglePlaces", dependencies: ["Vapor"]),
        .target(name: "App", dependencies: appTargetDependencies),
        .target(name: "Run", dependencies: ["App"]),
        .testTarget(name: "AppTests", dependencies: ["App"])
    ]
)

You can pass env variables directly to xcodebuild or if using fastlane you can set env vars in Fastfile. Wasn’t able to use xcode scheme env vars. Maybe someone can check again.

Xcode scheme env variables are for app run, not for build time, that's why this doesn't work.