M1 MacBook无法安装json gem v2.6.2问题求助

问题重现 #

执行命令：

sudo gem install json -v '2.6.2'

出现错误：

Building native extensions. This could take a while...
ERROR:  Error installing json:
    ERROR: Failed to build gem native extension.

    current directory: /Library/Ruby/Gems/2.6.0/gems/json-2.6.2/ext/json/ext/generator
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/bin/ruby -I /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0 -r ./siteconf20221018-37799-1wcwkww.rb extconf.rb
creating Makefile

current directory: /Library/Ruby/Gems/2.6.0/gems/json-2.6.2/ext/json/ext/generator
make "DESTDIR=" clean

current directory: /Library/Ruby/Gems/2.6.0/gems/json-2.6.2/ext/json/ext/generator
make "DESTDIR="
compiling generator.c
In file included from generator.c:1:
In file included from ./../fbuffer/fbuffer.h:5:
In file included from /Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX13.0.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/include/ruby-2.6.0/ruby.h:33:
/Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX13.0.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/include/ruby-2.6.0/ruby/ruby.h:24:10: fatal error: 'ruby/config.h' file not found
#include "ruby/config.h"
         ^~~~~~~~~~~~~~~
/Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX13.0.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/include/ruby-2.6.0/ruby/ruby.h:24:10: note: did not find header 'config.h' in framework 'ruby' (loaded from '/Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks')
1 error generated.
make: *** [generator.o] Error 1

make failed, exit code 2

Gem files will remain installed in /Library/Ruby/Gems/2.6.0/gems/json-2.6.2 for inspection.
Results logged to /Library/Ruby/Gems/2.6.0/extensions/universal-darwin-21/2.6.0/json-2.6.2/gem_make.out

用户怀疑是Xcode 14.1 Beta 3导致兼容问题，但不清楚如何切换Xcode版本，也不确定是否为该原因。

解决方案 #

1. 确认问题根源 #

错误提示中找不到ruby/config.h，确实和Xcode Beta版本的SDK兼容性有关——Beta版SDK对系统Ruby（2.6.0）的头文件支持存在缺失，导致编译失败。

2. 切换到正式版Xcode #

如果已安装正式版Xcode，执行以下步骤切换：

• 查看当前Xcode路径：

  xcode-select -p
  

• 切换到正式版（默认路径为/Applications/Xcode.app）：

  sudo xcode-select -s /Applications/Xcode.app/Contents/Developer
  

• 验证切换结果：

  xcode-select -p
  

  输出应为/Applications/Xcode.app/Contents/Developer

若未安装正式版，建议从App Store下载最新正式版，安装后重复上述切换步骤。

3. 不切换Xcode的临时修复 #

如果暂时无法切换Xcode版本，可通过指定编译参数强制安装：

sudo gem install json -v '2.6.2' -- --with-cflags="-Wno-error=implicit-function-declaration" --with-ldflags="-L/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib" --with-include-dir=/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/include

4. 长期解决方案：使用Ruby版本管理器 #

系统Ruby版本老旧且依赖系统环境，兼容性差。推荐用rbenv或rvm管理独立Ruby版本：

• 安装rbenv：

  brew install rbenv
  rbenv init
  

• 重启终端后，安装兼容的Ruby版本：

  rbenv install 2.7.6 # 可选择其他适配版本
  rbenv global 2.7.6
  

• 直接安装json gem：

  gem install json -v '2.6.2'
  

内容的提问来源于stack exchange，提问作者Berry Blue