目前 rails 版本为 4.2.5.1，准备升级为最新的 5.0 1.rvm list known

bash-3.2$ rvm list known 
# MRI Rubies
[ruby-]1.8.6[-p420]
[ruby-]1.8.7[-head] # security released on head
[ruby-]1.9.1[-p431]
[ruby-]1.9.2[-p330]
[ruby-]1.9.3[-p551]
[ruby-]2.0.0[-p648]
[ruby-]2.1[.10]
[ruby-]2.2[.5]
[ruby-]2.3[.1]
[ruby-]2.3-head
ruby-head

bash $ rvm install 2.3.1 --debug
ruby-2.3.1 - install
Log prefix: /home/chaotian/.rvm/log/1473228355_ruby-2.3.1/
Log filesystem: nfs
Log max name length: 250
Log file: /home/chaotian/.rvm/log/1473228355_ruby-2.3.1/remove.src.log
[2016-09-06 23:05:55] __rvm_rm_rf
__rvm_rm_rf () 
{ 
    __rvm_rm_rf_verbose "$@"
}
current path: /home/chaotian
GEM_HOME=/home/chaotian/.rvm/gems/ruby-2.1.5
command(2): __rvm_make -j4
ruby-2.3.1 - #compiling............................
Error running '__rvm_make -j4',
showing last 15 lines of /home/chaotian/.rvm/log/1473228355_ruby-2.3.1/make.log
vm.o:(.note.stapsdt+0x384): undefined reference to `ruby_cmethod__return_semaphore'
vm.o:(.note.stapsdt+0x3f8): undefined reference to `ruby_cmethod__return_semaphore'
vm.o:(.note.stapsdt+0x46c): undefined reference to `ruby_method__entry_semaphore'
vm.o:(.note.stapsdt+0x4dc): undefined reference to `ruby_cmethod__return_semaphore'
vm.o:(.note.stapsdt+0x550): undefined reference to `ruby_method__return_semaphore'
vm.o:(.note.stapsdt+0x5c4): undefined reference to `ruby_hash__create_semaphore'
vm.o:(.note.stapsdt+0x620): undefined reference to `ruby_cmethod__entry_semaphore'
vm.o:(.note.stapsdt+0x694): undefined reference to `ruby_cmethod__return_semaphore'
vm.o:(.note.stapsdt+0x708): undefined reference to `ruby_method__return_semaphore'
vm.o:(.note.stapsdt+0x778): undefined reference to `ruby_method__entry_semaphore'
vm.o:(.note.stapsdt+0x7e8): undefined reference to `ruby_cmethod__return_semaphore'
vm.o:(.note.stapsdt+0x85c): undefined reference to `ruby_cmethod__entry_semaphore'
collect2: ld returned 1 exit status
make: *** [miniruby] Error 1
++ return 2
There has been an error while running make. Halting the installation.
__rvm_rm_rf already gone: /home/chaotian/.rvm/tmp/22458*

尝试使用 rvm get head 也报错 ‘Could not download rvm-installer, get some help at #rvm IRC channel at freenode servers’ 同样 rvm get stable 也报错 ‘Could not download rvm-installer, get some help at #rvm IRC channel at freenode servers’ ---这里报错是因为 rvm 官网挂了，无法下载，同一时间我去验证的，公司连接的不是国内网络，不用翻墙 在 linux 环境升级