解决sudo xcrun gem install cocoapods 时报错 ‘ruby/config.h‘ file not found

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Building native extensions. This could take a while...
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/ext/builder.rb:76: warning: Insecure world writable dir /opt/homebrew/bin in PATH, mode 040777
ERROR: Error installing cocoapods:
ERROR: Failed to build gem native extension.

current directory: /Library/Ruby/Gems/2.6.0/gems/ffi-1.15.5/ext/ffi_c

/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 ./siteconf20220606-94797-1ua745k.rb extconf.rb
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:1565: warning: Insecure world writable dir /opt/homebrew/bin in PATH, mode 040777
checking for ffi.h... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers. Check the mkmf.log file for more details. You may
need configuration options.

Provided configuration options:
--with-opt-dir
--without-opt-dir
--with-opt-include
--without-opt-include={opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/bin/{ffi_c-dir}/include
--with-ffi_c-lib
--without-ffi_c-lib=${ffi_c-dir}/lib
--enable-system-libffi
--disable-system-libffi
--with-libffi-config
--without-libffi-config
--with-pkg-config
--without-pkg-config
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:467:in try_do': The compiler failed to generate an executable file. (RuntimeError) You have to install development tools first. from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:585:inblock in try_compile'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:534:in with_werror' from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:585:intry_compile'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:1109:in block in have_header' from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:959:inblock in checking_for'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:361:in block (2 levels) in postpone' from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:331:inopen'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:361:in block in postpone' from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:331:inopen'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:357:in postpone' from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:958:inchecking_for'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:1108:in have_header' from extconf.rb:10:insystem_libffi_usable?'
from extconf.rb:42:in `<main>'

To see why this extension failed to compile, please check the mkmf.log which can be found here:

/Library/Ruby/Gems/2.6.0/extensions/universal-darwin-20/2.6.0/ffi-1.15.5/mkmf.log

extconf failed, exit code 1

Gem files will remain installed in /Library/Ruby/Gems/2.6.0/gems/ffi-1.15.5 for inspection.
Results logged to /Library/Ruby/Gems/2.6.0/extensions/universal-darwin-20/2.6.0/ffi-1.15.5/gem_make.out
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根据提示查看日志 /Library/Ruby/Gems/2.6.0/extensions/universal-darwin-20/2.6.0/ffi-1.15.5/mkmf.log

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package configuration for libffi is not found
"xcrun clang -o conftest -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.1.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/include/ruby-2.6.0/universal-darwin20 -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.1.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/include/ruby-2.6.0/ruby/backward -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.1.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/include/ruby-2.6.0 -I. -D_XOPEN_SOURCE -D_DARWIN_C_SOURCE -D_DARWIN_UNLIMITED_SELECT -D_REENTRANT -g -Os -pipe -DHAVE_GCC_ATOMIC_BUILTINS conftest.c -L. -L/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib -L. -L/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.Internal.sdk/usr/local/lib -arch x86_64 -lruby.2.6 "
In file included from conftest.c:1:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.1.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/include/ruby-2.6.0/ruby.h:33:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.1.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.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.1.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 '/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/System/Library/Frameworks')
1 error generated.
checked program was:
/* begin */
1: #include "ruby.h"
2:
3: int main(int argc, char *argv)
4: {
5: return 0;
6: }
/ end */
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查看原因
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ccl@cclMacBookPro ruby-2.6.0 % cd $(xcode-select -p)/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/include/ruby-2.6.0

ccl@cclMacBookPro ruby-2.6.0 % ls
ruby ruby.h universal-darwin22
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解决方案

sudo ln -sf universal-darwin22 universal-darwin20
sudo ln -sf universal-darwin22 universal-darwin21