Data(contentsOf:) crash due to missing FoundationNetworking when using static linking

[MaxDesiatov]

This code having no references to FoundationNetworking causes a crash when compiled with swiftc -static-stdlib:

import Foundation

let str = try String(data: Data(contentsOf: URL(string: "https://httpbin.org/get")!), encoding: .utf8)!
print(str)

Data(contentsOf:) weakly (indirectly) links FoundationNetworking, which makes the linker exclude that library from static linking as seemingly unused if that's the only reference to networking in your code using Foundation on Linux.

This snippet works perfectly fine when compiled with swiftc -static-stdlib:

import Foundation
import FoundationNetworking

_ = URLSession.shared

let str = try String(data: Data(contentsOf: URL(string: "https://httpbin.org/get")!), encoding: .utf8)!
print(str)

Having a direct reference to symbols in FoundationNetworking (such as URLSession) is a recommended workaround as of Swift 5.7 and 5.6, and is likely to work in Swift 5.5 as well.

We're investigating if other solutions can be implemented in a future version of Swift.

Originally posted by @MaxDesiatov in swiftlang/swift#61372 (comment)