UserDefaults don't persist on Linux

[Diggory]

Sample code:

import Foundation

print("User Defaults")

#if os(macOS)
print("macOS")
#elseif os(Linux)
print("Linux")
#endif

//	Keys
struct MyDefaultsKeys {
	static let aSampleString 	= "aSampleStringDefault"
	static let aSampleNumber 	= "aSampleNumberDefault"
	static let aSampleDate 		= "aSampleNumberDate"
}

//	Get singleton
let defaults = UserDefaults.standard

// At start, must register factory defaults.
let factoryDefaults = [
	MyDefaultsKeys.aSampleString : "Hello World!",
	MyDefaultsKeys.aSampleNumber : 42.0,
	MyDefaultsKeys.aSampleDate : Date.distantPast,
] as [String : Any]

defaults.register(defaults: factoryDefaults)

//	Read
let aString = defaults.string(forKey: MyDefaultsKeys.aSampleString)
print("aString: \(aString ?? "NO VALUE FOR \(MyDefaultsKeys.aSampleString) IN DEFAULTS")")

let aNumber = defaults.double(forKey: MyDefaultsKeys.aSampleNumber)
print("aNumber: \(aNumber)")

if let aDate = defaults.object(forKey: MyDefaultsKeys.aSampleDate) as? Date {
	print("aDate: \(aDate)")
} else {
	print("NO VALUE FOR \(MyDefaultsKeys.aSampleDate) IN DEFAULTS")
}

//	Write
defaults.set("I have changed!", forKey: MyDefaultsKeys.aSampleString)
defaults.set(1234567, forKey: MyDefaultsKeys.aSampleNumber)
defaults.set(Date(), forKey: MyDefaultsKeys.aSampleDate)

Output:

macOS:

First Run

User Defaults
macOS
aString: Hello World!
aNumber: 42.0
aDate: 0001-01-01 12:00:00 am +0000
Program ended with exit code: 0

Second Run

User Defaults
macOS
aString: I have changed!
aNumber: 1234567.0
aDate: 2023-10-29 7:34:56 am +0000
Program ended with exit code: 0

Linux

First Run

Build complete! (2.39s)
User Defaults
Linux
aString: Hello World!
aNumber: 42.0
aDate: 0000-12-30 00:00:00 +0000

Second Run

Build complete! (0.45s)
User Defaults
Linux
aString: Hello World!
aNumber: 42.0
aDate: 0000-12-30 00:00:00 +0000