Failed to parse the manifest file, in my Xcode Swift Package Manger - xcode

Question

I am install Firebase via Swift Package Manager. I attempted to use the Swift Package Manager to automatically install this library from a Github repository.
When I build the project I received an error saying that "Failed to parse the manifest file". Package.swift file is in my "firebase-ios-sdk-master" subdirectory of my project.
Bellowing is my Package.swift file:
import PackageDescription
import class Foundation.ProcessInfo
let firebaseVersion = "9.3.0"
let package = Package(
name: "Firebase",
platforms: [.iOS(.v11), .macOS(.v10_12), .tvOS(.v12), .watchOS(.v7)],
products: [
.library(
name: "FirebaseAnalytics",
targets: ["FirebaseAnalyticsTarget"]
),
//...
],
dependencies: [
.package(name: "Firebase",
url: "https://github.com/firebase/firebase-ios-sdk.git",
from: "8.0"
),
.package(
name: "Promises",
url: "https://github.com/google/promises.git",
"2.1.0" ..< "3.0.0"
),
//...
],
targets: [
.target(
name: "Firebase",
dependencies: [
.product(name: "FirebaseAuth", package: "Firebase"),
],
path: "CoreOnly/Sources",
publicHeadersPath: "./"
),
.target(
name: "FirebaseCore",
dependencies: [
"Firebase",
"FirebaseCoreDiagnostics",
"FirebaseCoreInternal",
.product(name: "GULEnvironment", package: "GoogleUtilities"),
.product(name: "GULLogger", package: "GoogleUtilities"),
],
path: "FirebaseCore/Sources",
publicHeadersPath: "Public",
cSettings: [
.headerSearchPath("../.."),
.define("Firebase_VERSION", to: firebaseVersion),
// TODO: - Add support for cflags cSetting so that we can set the -fno-autolink option
],
linkerSettings: [
.linkedFramework("UIKit", .when(platforms: [.iOS, .tvOS])),
.linkedFramework("AppKit", .when(platforms: [.macOS])),
]
),
//...
],
cLanguageStandard: .c99,
cxxLanguageStandard: CXXLanguageStandard.gnucxx14
)
if ProcessInfo.processInfo.environment["FIREBASECI_USE_LATEST_GOOGLEAPPMEASUREMENT"] != nil {
if let GoogleAppMeasurementIndex = package.dependencies
.firstIndex(where: { $0.name == "GoogleAppMeasurement" }) {
package.dependencies[GoogleAppMeasurementIndex] = .package(
name: "GoogleAppMeasurement",
url: "https://github.com/google/GoogleAppMeasurement.git",
.branch("main")
)
}
}