#if canImport(Darwin)import Darwin#elseif canImport(Glibc)import Glibc#elseif canImport(Musl)import Musl#endifimport Foundation enum PosixSpawnFileActionsCloseFrom {    enum CloseFromError: LocalizedError {        case descriptorEnumerationFailed(String)        case actionFailed(Int32)         var errorDescription: String? {            switch self {            case let .descriptorEnumerationFailed(details):                "Could not enumerate /proc/self/fd: \(details)"            case let .actionFailed(code):                "Could not configure descriptor cleanup: \(String(cString: strerror(code))) (\(code))"            }        }    }     static func descriptorsToClose(        startingAt minimumFileDescriptor: Int32,        contentsOfDirectory: (String) throws -> [String] = FileManager.default.contentsOfDirectory(atPath:)) throws        -> [Int32]    {        let entries: [String]        do {            entries = try contentsOfDirectory("/proc/self/fd")        } catch {            throw CloseFromError.descriptorEnumerationFailed(error.localizedDescription)        }        return entries.compactMap(Int32.init)            .filter { $0 >= minimumFileDescriptor }            .sorted()    }     #if canImport(Glibc) || canImport(Musl)    static func addCloseFrom(        _ fileActions: inout posix_spawn_file_actions_t,        startingAt minimumFileDescriptor: Int32) throws    {        #if canImport(Glibc)        try self.check(posix_spawn_file_actions_addclosefrom_np(&fileActions, minimumFileDescriptor))        #else        for descriptor in try self.descriptorsToClose(startingAt: minimumFileDescriptor) {            try self.check(posix_spawn_file_actions_addclose(&fileActions, descriptor))        }        #endif    }     private static func check(_ result: Int32) throws {        guard result == 0 else {            throw CloseFromError.actionFailed(result)        }    }    #endif}