How 'bout I do anyway? 😒

ProcessSerialNumber.swift

//
//  ProcessSerialNumber.swift
//  
//  Created by Stephan Casas on 2/28/24.
//

extension ProcessSerialNumber {

    /// Create a new `ProcessSerialNumber` using the given process identifier.
    init?(_ pid: pid_t) {
        var psn = ProcessSerialNumber(
            highLongOfPSN: 0,
            lowLongOfPSN: 0);
        
        guard ProcessSerialNumber.getProcessForPid(
            pid, &psn
        ) == .zero else {
            return nil;
        }
        
        self = psn;
    }
    
    /// Alias to the deprecated-but-still-widely-used `GetProcessForPID` function.
    static func getProcessForPid(
        _ pid: pid_t,
        _ psn: UnsafeMutablePointer<ProcessSerialNumber>
    ) -> OSStatus {
        guard
            let HIServicesFramework = dlopen(
                "/System/Library/Frameworks/ApplicationServices.framework/Frameworks/HIServices.framework/HIServices",
                RTLD_NOW),
            let $GetProcessForPID = dlsym(
                HIServicesFramework,
                "GetProcessForPID")
        else {
            return 1;
        }
        
        return unsafeBitCast(
            $GetProcessForPID,
            to: (@convention(c) (
                pid_t,
                UnsafeMutablePointer<ProcessSerialNumber>
            ) -> OSStatus).self
        )(pid, psn);
    }
    
}