查来查去查不到问题，后来在*看到：
http://*.com/questions/22352838/ruby-gem-install-json-fails-on-mavericks-and-xcode-5-1-unknown-argument-mul/22384591#22384591
Issue already addressed by Ruby: https://bugs.ruby-lang.org/issues/9624 now we just need to wait for Apple to update their ruby version (2.0.0p247) to the one after the latest one (2.0.0p451) which hasn't come out yet ... (or brew/macport it)
To address the issue you can install the most recent version of ruby as described by @Sash. You can use the following commands to do so. In case you already have installed rvm, you don't need to reinstall it.
#Install rvm
\curl -sSL https://get.rvm.io | bash -s stable
#Install ruby version 2.0.0-p451
rvm install ruby-2.0.0-p451
#Print ruby version to verify that it was installed successfully
ruby -v
#Install json gem
sudo gem install json
才发现可能是ruby版本问题。。
Last login: Sat May 17 08:35:42 on console
Narumis-MacBook-Air:~ narumi$ ruby -v
ruby 2.0.0p247 (2013-06-27 revision 41674) [universal.x86_64-darwin13]
Narumis-MacBook-Air:~ narumi$ rails -v
Rails 4.0.3
Narumis-MacBook-Air:~ narumi$ mysql -v
-bash: mysql: command not found
Narumis-MacBook-Air:~ narumi$ sudo gem install mysql2
Password:
Fetching: mysql2-0.3.16.gem (100%)
Building native extensions. This could take a while...
ERROR: Error installing mysql2:
ERROR: Failed to build gem native extension.
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby extconf.rb
checking for ruby/thread.h... yes
checking for rb_thread_call_without_gvl() in ruby/thread.h... yes
checking for rb_thread_blocking_region()... yes
checking for rb_wait_for_single_fd()... yes
checking for rb_hash_dup()... yes
checking for rb_intern3()... yes
-----
Using mysql_config at /usr/local/mysql/bin/mysql_config
-----
checking for mysql.h... yes
checking for errmsg.h... yes
checking for mysqld_error.h... yes
-----
Setting rpath to /usr/local/mysql/lib
-----
creating Makefile
make "DESTDIR=" clean
make "DESTDIR="
compiling client.c
compiling infile.c
compiling mysql2_ext.c
compiling result.c
linking shared-object mysql2/mysql2.bundle
clang: error: unknown argument: '-multiply_definedsuppress' [-Wunused-command-line-argument-hard-error-in-future]
clang: note: this will be a hard error (cannot be downgraded to a warning) in the future
make: *** [mysql2.bundle] Error 1
make failed, exit code 2
Gem files will remain installed in /Library/Ruby/Gems/2.0.0/gems/mysql2-0.3.16 for inspection.
Results logged to /Library/Ruby/Gems/2.0.0/extensions/universal-darwin-13/2.0.0/mysql2-0.3.16/gem_make.out
Narumis-MacBook-Air:~ narumi$ bundle exec rails s
Could not locate Gemfile
Narumis-MacBook-Air:~ narumi$ bundle -v
Bundler version 1.6.0.rc
Narumis-MacBook-Air:~ narumi$ sudo bundle install
Could not locate Gemfile
Narumis-MacBook-Air:~ narumi$ sudo gem install mysql2 -v0.3.15
Fetching: mysql2-0.3.15.gem (100%)
Building native extensions. This could take a while...
ERROR: Error installing mysql2:
ERROR: Failed to build gem native extension.
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby extconf.rb
checking for ruby/thread.h... yes
checking for rb_thread_call_without_gvl() in ruby/thread.h... yes
checking for rb_thread_blocking_region()... yes
checking for rb_wait_for_single_fd()... yes
checking for rb_hash_dup()... yes
checking for rb_intern3()... yes
-----
Using mysql_config at /usr/local/mysql/bin/mysql_config
-----
checking for mysql.h... yes
checking for errmsg.h... yes
checking for mysqld_error.h... yes
-----
Setting rpath to /usr/local/mysql/lib
-----
creating Makefile
make "DESTDIR=" clean
make "DESTDIR="
compiling client.c
compiling infile.c
compiling mysql2_ext.c
compiling result.c
linking shared-object mysql2/mysql2.bundle
clang: error: unknown argument: '-multiply_definedsuppress' [-Wunused-command-line-argument-hard-error-in-future]
clang: note: this will be a hard error (cannot be downgraded to a warning) in the future
make: *** [mysql2.bundle] Error 1
make failed, exit code 2
Gem files will remain installed in /Library/Ruby/Gems/2.0.0/gems/mysql2-0.3.15 for inspection.
Results logged to /Library/Ruby/Gems/2.0.0/extensions/universal-darwin-13/2.0.0/mysql2-0.3.15/gem_make.out
Narumis-MacBook-Air:~ narumi$
[Restored]
Narumis-MacBook-Air:~ narumi$ sudo gem install git
Password:
Fetching: git-1.2.6.gem (100%)
Successfully installed git-1.2.6
Parsing documentation for git-1.2.6
Installing ri documentation for git-1.2.6
1 gem installed
Narumis-MacBook-Air:~ narumi$ sudo gem install rvm
Fetching: rvm-1.11.3.9.gem (100%)
Successfully installed rvm-1.11.3.9
Parsing documentation for rvm-1.11.3.9
Installing ri documentation for rvm-1.11.3.9
1 gem installed
Narumis-MacBook-Air:~ narumi$ sudo gem install homebrew
ERROR: Could not find a valid gem 'homebrew' (>= 0) in any repository
ERROR: Possible alternatives: hebrew, homespree, homer, home_run, honeydew
Narumis-MacBook-Air:~ narumi$ sudo rvm install mysql2
sudo: rvm: command not found
Narumis-MacBook-Air:~ narumi$ ruby -e "$(curl -fsSL https://raw.github.com/Homebrew/homebrew/go/install)"
==> This script will install:
/usr/local/bin/brew
/usr/local/Library/...
/usr/local/share/man/man1/brew.1
==> The following directories will be made group writable:
/usr/local/.
==> The following directories will have their group set to admin:
/usr/local/.
Press RETURN to continue or any other key to abort
==> /usr/bin/sudo /bin/chmod g+rwx /usr/local/.
Password:
==> /usr/bin/sudo /usr/bin/chgrp admin /usr/local/.
==> /usr/bin/sudo /bin/mkdir /Library/Caches/Homebrew
==> /usr/bin/sudo /bin/chmod g+rwx /Library/Caches/Homebrew
==> Downloading and installing Homebrew...
remote: Counting objects: 172949, done.
error: RPC failed; result=56, HTTP code = 200
fatal: The remote end hung up unexpectedly
fatal: protocol error: bad pack header
Failed during: git fetch origin master:refs/remotes/origin/master -n
Narumis-MacBook-Air:~ narumi$ sudo ruby -e "$(curl -fsSL https://raw.github.com/Homebrew/homebrew/go/install)"
Password:
Don't run this as root!
Narumis-MacBook-Air:~ narumi$ ruby -e "$(curl -fsSL https://raw.github.com/Homebrew/homebrew/go/install)"
It appears Homebrew is already installed. If your intent is to reinstall you
should do the following before running this installer again:
rm -rf /usr/local/Cellar /usr/local/.git && brew cleanup
Narumis-MacBook-Air:~ narumi$ rm -rf /usr/local/.git
Narumis-MacBook-Air:~ narumi$ rm -rf /usr/local/brew
Narumis-MacBook-Air:~ narumi$ ruby -e "$(curl -fsSL https://raw.github.com/Homebrew/homebrew/go/install)"
==> This script will install:
/usr/local/bin/brew
/usr/local/Library/...
/usr/local/share/man/man1/brew.1
Press RETURN to continue or any other key to abort
==> /usr/bin/sudo /bin/chmod g+rwx /Library/Caches/Homebrew
Password:
==> Downloading and installing Homebrew...
remote: Counting objects: 172949, done.
remote: Compressing objects: 100% (48276/48276), done.
remote: Total 172949 (delta 123533), reused 172949 (delta 123533)
Receiving objects: 100% (172949/172949), 33.78 MiB | 2.20 MiB/s, done.
Resolving deltas: 100% (123533/123533), done.
From https://github.com/Homebrew/homebrew
* [new branch] master -> origin/master
HEAD is now at 037e06d Move agedu to headonly
==> Installation successful!
==> Next steps
Run `brew doctor` before you install anything
Run `brew help` to get started
Narumis-MacBook-Air:~ narumi$ brew list
Narumis-MacBook-Air:~ narumi$ sudo chown -R $narumi /usr/loacal
Password:
usage: chown [-fhv] [-R [-H | -L | -P]] owner[:group] file ...
chown [-fhv] [-R [-H | -L | -P]] :group file ...
Narumis-MacBook-Air:~ narumi$ sudo chown -R narumi /usr/loacal
chown: /usr/loacal: No such file or directory
Narumis-MacBook-Air:~ narumi$ sudo chown -R narumi /usr/local
Narumis-MacBook-Air:~ narumi$ sudo chown -R $narumi /usr/local
usage: chown [-fhv] [-R [-H | -L | -P]] owner[:group] file ...
chown [-fhv] [-R [-H | -L | -P]] :group file ...
Narumis-MacBook-Air:~ narumi$ brew doctor
^C
Narumis-MacBook-Air:~ narumi$ brew doctor
Your system is ready to brew.
Narumis-MacBook-Air:~ narumi$ brew install mysql
==> Installing mysql dependency: openssl
==> Downloading https://downloads.sf.net/project/machomebrew/Bottles/openssl-1.0.1g.mavericks.bottle.tar.g
######################################################################## 100.0%
==> Pouring openssl-1.0.1g.mavericks.bottle.tar.gz
==> Caveats
A CA file has been bootstrapped using certificates from the system
keychain. To add additional certificates, place .pem files in
/usr/local/etc/openssl/certs
and run
/usr/local/opt/openssl/bin/c_rehash
This formula is keg-only, so it was not symlinked into /usr/local.
Mac OS X already provides this software and installing another version in
parallel can cause all kinds of trouble.
The OpenSSL provided by OS X is too old for some software.
Generally there are no consequences of this for you. If you build your
own software and it requires this formula, you'll need to add to your
build variables:
LDFLAGS: -L/usr/local/opt/openssl/lib
CPPFLAGS: -I/usr/local/opt/openssl/include
==> Summary