你可以使用Darling在Linux本机运行Xcode:

Darling是一个转换层，可以让你在Linux上运行macOS软件

安装完成后，你可以通过命令行开发工具安装Xcode。

如果你运行VMware Player或Workstation(或者VirtualBox，我不确定它是否支持Mac OS X，但可能)，然后是Mac OS X Server(客户端不能合法虚拟化)。当然，在这种情况下，你是在OS X上运行XCode，但你的主机可能是linux。

I really wanted to comment, not answer. But just to be precise, OSX is not based on BSD, it is an evolution of NeXTStep. The NeXTStep OS utilizes the Mach kernel developed by CMU. It was originally designed as a MicroKernel, but due to performance constraints, they eventually decided they needed to include the Unix portion of the API into the kernel itself and so a BSD-compatible "server" (originally intended to process requests for BSD-compatible kernel messages) was moved into the kernel, making it a Monolithic kernel. It may be BSD compatible in the programming API, but it is NOT BSD.

操作系统的其余部分涉及到objecvec(在Stepstone和GNU/GCC的Richard Stallman的安排下)和基于“显示后脚本”技术的GUI…有点像X服务器，但是带有后记命令。OS X将显示Postscript更改为显示PDF，并将一般硬件要求提高了1000倍(NeXT可以运行8-16MB，现在需要GB)。

Due to the close marriage of GCC and Objective C and NeXT, your best bet at running XCode natively under Linux would be to do a port (if you can get ahold of the source - good luck) utilizing the GNUStep libraries. Originally designed for NextStep and then OpenStep compatibility, I've heard they are now more-or-less Cocoa compatible, but I've not played with any of it in almost 2 decades. Of course that only gets you as far as ObjC, not Swift, and I don't know if Apple is going to OpenSource it.

Xcode的底层工具链(gcc编译器家族，gdb调试器等)都是开源的，并且通用于Unix和Linux平台。但是IDE——编辑器、项目管理、索引、导航、构建系统、图形调试器、可视化数据建模、SCM系统、重构、项目快照等——是Mac OS X Cocoa应用程序，并且不可移植。

OSX基于BSD，而不是Linux。你不能在Linux机器上运行Xcode。

如果您计划在Linux上使用Mac虚拟机，请检查Docker-OSX。它提供了一种使用Docker预构建的Mac vm的简单方法。

要了解更多关于在非苹果硬件上运行苹果软件的合法性，请阅读这篇文章:Hackintosh、OSX-KVM或Docker-OSX合法吗?