https://developer.apple.com/forums/thread/731090
升级到Xcode 15后，原先Xcode14可以编译的项目出现大量Duplicate symbols，且引用报错指向同一个路径（一般为Framework）下的同一个文件。经过查找相关解决，可通过添加设置改正。
✅解决方案：
在Xcode -> Target -> Build Setting -> Other Linker Flags 添加一行"-ld64" 即可解决该问题
原因：
Xcode 15 beta includes a new linker, known as `ld_prime`. This has a bunch of benefits, not least being the support for mergeable libraries, per WWDC 2023 Session 10268 [Meet mergeable libraries](https://developer.apple.com/videos/play/wwdc2023/10268/). However, any time you rewrite something that complex you inevitably run into the odd issue. Normally I'd suggest you file a bug about this, but we already have a bug report about this one (r. 110340167).
In the meantime, you should be able to work around it by reverting to the old linker. The linker has two options, `-ld64` and `-ld_prime`, that override its default algorithm for choosing a back end.Xcode 15测试版包含一个新的链接器，称为ld_prime。根据WWDC 2023 Session 10268 Meet mergeable libraries，这有很多好处，尤其是支持可合并库。然而，每当你重写如此复杂的东西时，你不可避免地会遇到奇怪的问题。通常我建议你提交一个关于这个的bug，但我们已经有了关于这个bug的报告（r.110340167）。
同时，✅您应该能够通过恢复到旧的链接器来解决它✅。链接器有两个选项，-ld64和-ld_prime，它们覆盖了用于选择后端的默认算法。
添加设置可以选择使用旧的链接器 而不是默认的新的 -ld_prime 链接器。
⚠️警告：
-ld64 is deprecated, use -ld_classic instead
报警告，换成下面方案：
在Xcode -> Target -> Build Setting -> Other Linker Flags 添加一行"-ld_classic" 即可解决该问题