Question

运行此命令时收到以下错误消息：

gem install rails -v 4.2.4

这是错误：

/Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/yaml.rb:5: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.
/Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require': dlopen(/Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/x86_64-darwin15/psych.bundle, 9): Library not loaded: /usr/local/opt/libyaml/lib/libyaml-0.2.dylib (LoadError)
  Referenced from: /Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/x86_64-darwin15/psych.bundle
  Reason: image not found - /Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/x86_64-darwin15/psych.bundle
    from /Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/psych.rb:7:in `<top (required)>'
    from /Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/yaml.rb:6:in `<top (required)>'
    from /Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems.rb:628:in `load_yaml'
    from /Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/config_file.rb:326:in `load_file'
    from /Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/config_file.rb:198:in `initialize'
    from /Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/gem_runner.rb:75:in `new'
    from /Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/gem_runner.rb:75:in `do_configuration'
    from /Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/gem_runner.rb:40:in `run'
    from /Users/adamgoldberg/.rvm/rubies/ruby-2.3.0/bin/gem:21:in `<main>'

请帮忙 - 这让我做恶梦

Answer 1

看起来您的ruby安装缺少心理（对于YAML输出）。

使用 Homebrew 安装libyaml：http://brew.sh;然后尝试gem install rails -v 4.2.4

$ brew info libyaml
libyaml: stable 0.1.6 (bottled)
YAML Parser
http://pyyaml.org/wiki/LibYAML
Not installed
From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/libyaml.rb
==> Options
--universal
    Build a universal binary

$ brew install libyaml
==> Downloading https://homebrew.bintray.com/bottles/libyaml-0.1.6_1.el_capitan.bottle.tar.gz
######################################################################## 100.0%
==> Pouring libyaml-0.1.6_1.el_capitan.bottle.tar.gz
  /usr/local/Cellar/libyaml/0.1.6_1: 8 files, 312.8K

重新安装RUBY

如果上述解决方案不适合您，请使用 rvm 或 rbenv 重新安装Ruby，

1）尝试接受此答案的说明：https://stackoverflow.com/a/38194139/1076207

-OR -

2）删除所有 rvm 文件，然后重新安装 rvm ：https://stackoverflow.com/a/38158619/1076207

-OR -

3）删除所有 rvm 文件，然后安装 rbenv ：https://stackoverflow.com/a/38194231/1076207

使用上述三个选项之一后，使用http://bundler.io安装Rails：

$ mkdir ~/Documents/Repo
$ cd ~/Documents/Repo
$ gem install bundler
[…]
$ bundle init
Writing new Gemfile to /Users/username/Documents/Repo/Gemfile
$ echo "gem 'rails', '4.2.4'" >> Gemfile
$ bundle install
[…]
$ bundle exec rails new project_name
[…]
$ cd project_name

就个人而言，我建议3）切换到rbenv-I。

Answer 2

错误本身清楚地表明您应首先安装libyaml然后重新安装ruby。您可以通过运行以下命令来完成此操作。

sudo apt-get install libtool

rvm package install libyaml 

rvm reinstall ruby-2.3.0

有关详情，请参阅this answer

gem install rails -v 4.2.4安装失败

2 个答案: