Xcode12 编译报错: built for iOS, for

升级Xcode12后，编译项目时，可能会出现以下错误：

building for iOS Simulator, but linking in object：

building for iOS Simulator, but linking in object ... file built for iOS, for architecture arm64

Embedded binary is not signed with the same certificate:

Embedded binary is not signed with the same certificate as the parent app. Verify the embedded binary target's code sign settings match the parent app's.
Embedded Binary Signing Certificate: XXX 
Parent App Signing Certificate: XXX 

.app" couldn’t be opened because you don’t have permission to view it.：

The file "XXX.app" couldn’t be opened because you don’t have permission to view it.

产生这些报错的根本原因是新版本的Xcode 12更改了编译架构的设置方式：

旧版本的Xcode编译架构设置方式: 用Xcode打开项目 -> Project -> PROJECT -> Build Setting ->

1. 首先在Architectures -> Valid Architectures -> 设置可用的编译架构指令集
2. 然后在User-Defined -> EXCLUDED_ARCHS -> 设置排除的编译架构指令集

而新版Xcode12的编译架构设置方式: 用Xcode打开项目 -> Project -> PROJECT -> Build Setting ->

1. 首先在Architectures -> Excluded Architectures -> 排除的编译架构指令集
2. 然后在User-Defined -> VALID_ARCHS -> 设置可用的编译架构指令集

因此，解决上述问题的方案就是在新版的Xcode12中设置：

1. 在Architectures -> Excluded Architectures -> 设置排除的编译架构指令集为"arm64"。（建议只设置Debug模式，Release模式还是要支持arm64的，否则打包后无法在真机上海安装）
2. 同时，删除User-Defined中的VALID_ARCHS栏，即可用的编译架构指令集的设置（操作方法：选择PROJECT -> Build Setting ->User-Defined ->选中VALID_ARCHS，直接按Delete键）。