在CentOS 5.8上安装rvm之后：
[rails@localhost ~]$ rvm -v rvm 1.16.17 [rails@localhost ~]$ which ruby ~/.rvm/rubies/ruby-1.9.3-p286/bin/ruby [rails@localhost ~]$ ruby -v ruby 1.9.3p286 (2012-10-12 revision 37165) [i686-linux] [rails@localhost ~]$ which gem ~/.rvm/rubies/ruby-1.9.3-p286/bin/gem
有一个警告：
$ gem -v /home/rails/.rvm/rubies/ruby-1.9.3-p286/lib/ruby/1.9.1/yaml.rb:56:in `<top (required)>': It seems your ruby installation is missing psych (for YAML output). To eliminate this warning, please install libyaml and reinstall your ruby. 1.8.24
我遵循了一些build议 ：
$ rvm pkg install libyaml Fetching yaml-0.1.4.tar.gz to /home/rails/.rvm/archives Extracting yaml-0.1.4.tar.gz to /home/rails/.rvm/src Prepare yaml in /home/rails/.rvm/src/yaml-0.1.4. Configuring yaml in /home/rails/.rvm/src/yaml-0.1.4. Compiling yaml in /home/rails/.rvm/src/yaml-0.1.4. Installing yaml to /home/rails/.rvm/usr Please note that it's required to reinstall all rubies: rvm reinstall all --force
接着：
$ rvm reinstall all --force Removing /home/rails/.rvm/src/ruby-1.8.7-p371... Removing /home/rails/.rvm/rubies/ruby-1.8.7-p371... No binary rubies available for: centos/5.8/i386/ruby-1.8.7-p371. Continuing with compilation. Please read 'rvm mount' to get more information on binary rubies. Installing Ruby from source to: /home/rails/.rvm/rubies/ruby-1.8.7-p371, this may take a while depending on your cpu(s)... ruby-1.8.7-p371 - #downloading ruby-1.8.7-p371, this may take a while depending on your connection... ruby-1.8.7-p371 - #extracting ruby-1.8.7-p371 to /home/rails/.rvm/src/ruby-1.8.7-p371 ruby-1.8.7-p371 - #extracted to /home/rails/.rvm/src/ruby-1.8.7-p371 Applying patch /home/rails/.rvm/patches/ruby/1.8.7/stdout-rouge-fix.patch Applying patch /home/rails/.rvm/patches/ruby/1.8.7/no_sslv2.diff ruby-1.8.7-p371 - #configuring ruby-1.8.7-p371 - #compiling ruby-1.8.7-p371 - #installing Removing old Rubygems files... Installing rubygems-1.8.24 for ruby-1.8.7-p371 ... Installation of rubygems completed successfully. Saving wrappers to '/home/rails/.rvm/bin'. ruby-1.8.7-p371 - #adjusting #shebangs for (gem irb erb ri rdoc testrb rake). ruby-1.8.7-p371 - #importing default gemsets (/home/rails/.rvm/gemsets/) Install of ruby-1.8.7-p371 - #complete Please be aware that you just installed a ruby that requires 2 patches just to be compiled on up to date linux system. This may have known and unaccounted for security vulnerabilities. Please consider upgrading to Ruby 1.9.3-286 which will have all of the latest security patches. Making gemset ruby-1.8.7-p371 pristine. Making gemset ruby-1.8.7-p371@global pristine. Removing /home/rails/.rvm/src/ruby-1.9.3-p286... Removing /home/rails/.rvm/rubies/ruby-1.9.3-p286... No binary rubies available for: centos/5.8/i386/ruby-1.9.3-p286. Continuing with compilation. Please read 'rvm mount' to get more information on binary rubies. Installing Ruby from source to: /home/rails/.rvm/rubies/ruby-1.9.3-p286, this may take a while depending on your cpu(s)... ruby-1.9.3-p286 - #downloading ruby-1.9.3-p286, this may take a while depending on your connection... ruby-1.9.3-p286 - #extracting ruby-1.9.3-p286 to /home/rails/.rvm/src/ruby-1.9.3-p286 ruby-1.9.3-p286 - #extracted to /home/rails/.rvm/src/ruby-1.9.3-p286 ruby-1.9.3-p286 - #configuring ruby-1.9.3-p286 - #compiling ruby-1.9.3-p286 - #installing Removing old Rubygems files... Installing rubygems-1.8.24 for ruby-1.9.3-p286 ... Installation of rubygems completed successfully. Saving wrappers to '/home/rails/.rvm/bin'. ruby-1.9.3-p286 - #adjusting #shebangs for (gem irb erb ri rdoc testrb rake). ruby-1.9.3-p286 - #importing default gemsets (/home/rails/.rvm/gemsets/) Install of ruby-1.9.3-p286 - #complete Making gemset ruby-1.9.3-p286 pristine. Making gemset ruby-1.9.3-p286@global pristine.
太糟糕了，警告仍然存在：
$ gem -v /home/rails/.rvm/rubies/ruby-1.9.3-p286/lib/ruby/1.9.1/yaml.rb:56:in `<top (required)>': It seems your ruby installation is missing psych (for YAML output). To eliminate this warning, please install libyaml and reinstall your ruby. 1.8.24
我怎样才能摆脱警告？
更新:(应用rvm reinstall 1.9.3 --movable ）
$ rvm reinstall 1.9.3 --movable Removing /home/rails/.rvm/src/ruby-1.9.3-p286... Removing /home/rails/.rvm/rubies/ruby-1.9.3-p286... Fetching yaml-0.1.4.tar.gz to /home/rails/.rvm/archives Extracting yaml-0.1.4.tar.gz to /home/rails/.rvm/src Prepare yaml in /home/rails/.rvm/src/yaml-0.1.4. Configuring yaml in /home/rails/.rvm/src/yaml-0.1.4. Compiling yaml in /home/rails/.rvm/src/yaml-0.1.4. Installing yaml to /home/rails/.rvm/rubies/ruby-1.9.3-p286 Installing Ruby from source to: /home/rails/.rvm/rubies/ruby-1.9.3-p286, this may take a while depending on your cpu(s)... ruby-1.9.3-p286 - #downloading ruby-1.9.3-p286, this may take a while depending on your connection... ruby-1.9.3-p286 - #extracting ruby-1.9.3-p286 to /home/rails/.rvm/src/ruby-1.9.3-p286 ruby-1.9.3-p286 - #extracted to /home/rails/.rvm/src/ruby-1.9.3-p286 Applying patch /home/rails/.rvm/patches/ruby/1.9.3/ruby-multilib.patch Error running 'patch -F 25 -p1 -N -f -i /home/rails/.rvm/patches/ruby/1.9.3/ruby-multilib.patch', please read /home/rails/.rvm/log/ruby-1.9.3-p286/patch.apply.ruby-multilib.log There has been an error applying the specified patches. Halting the installation. Making gemset ruby-1.9.3-p286 pristine. Making gemset ruby-1.9.3-p286@global pristine.
rvm pkg install libyaml ，重新安装ruby 1.9.3：
rvm reinstall 1.9.3 --with-libyaml-dir=/home/rails/.rvm/usr
信用： https ： //stackoverflow.com/a/12882906/88597
尝试这个：
rvm get head rvm reinstall 1.9.3 --movable
sudo apt-get install libtool sudo apt-get install libyaml-dev rvm reinstall 1.9.3
我已经尝试了所有，这解决了我的问题。
我想你必须安装libyaml：
$ wget http://pyyaml.org/download/libyaml/yaml-0.1.4.tar.gz $ tar xzvf yaml-0.1.4.tar.gz $ cd yaml-0.1.4 $ ./configure --prefix=/usr/local $ make $ make install
请参阅： http : //collectiveidea.com/blog/archives/2011/10/31/install-ruby-193-with-libyaml-on-centos/
你可以从另一个版本库（我使用repoforge.org）安装libyaml-devel：
sudo rpm --import http://apt.sw.be/RPM-GPG-KEY.dag.txt sudo rpm -ivh http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.3-1.el6.rf.x86_64.rpm sudo yum install -y libyaml-devel