难以安装和运行rails（/ usr / local / bin / rails：没有这样的文件或目录），曾经恢复到早期的rails版本

Question

在我将rails换回早期版本的项目之后执行rails new blah时出错

导轨工作正常，我可以做rails new blah

我想测试一个项目的更改rails版本。到目前为止，我的经验是改变项目的rails版本不会改变全球的rails！所以我的经验是，当CDing出一个目录并做rails -v时我仍然在5.2.2.1

所以我做了一个项目，目的是回到导轨0.8.0（就像测试一样！）

~/rubymac/test16$ cat Gemfile | grep "^gem 'rails'"
gem 'rails', '0.8.0'
~/rubymac/test16$

我做了bundle update rails

并且没有错误，我在Gemfile.lock中看到rails 0.8.0似乎在那里被指定所以我猜这有用了。

然后我做了cd ..并且做了rails -v期待（仍然）看到rails 5.2.2.1这是我过去的经验，当我把一个项目放回稍早版本的rails。但是rails -v没有用。并且rails new blah123也没有工作。

~/rubymac$ rails -v
(in /usr/local/lib/ruby/gems/2.5.0/gems/rails-0.8.0)
rake aborted!
LoadError: cannot load such file -- rake/rdoctask
/usr/local/lib/ruby/gems/2.5.0/gems/rails-0.8.0/Rakefile:3:in `<top (required)>'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.2/exe/rake:27:in `<top (required)>'
(See full trace by running task with --trace)
~/rubymac$

和

~/rubymac$ rails new blah2432
(in /usr/local/lib/ruby/gems/2.5.0/gems/rails-0.8.0)
rake aborted!
LoadError: cannot load such file -- rake/rdoctask
/usr/local/lib/ruby/gems/2.5.0/gems/rails-0.8.0/Rakefile:3:in `<top (required)>'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.2/exe/rake:27:in `<top (required)>'
(See full trace by running task with --trace)
~/rubymac$

所以我搜索并发现了这个问题new rails project error Rails 3。这表明gem install rails -v3.0.9

所以我做了gem install rails -v5.2.2.1

它没有错误

~/rubymac$ gem install rails -v5.2.2.1
Successfully installed rails-5.2.2.1
Parsing documentation for rails-5.2.2.1
Done installing documentation for rails after 0 seconds
1 gem installed
~/rubymac$

但是rails -v仍然不起作用

~/rubymac$ rails -v
(in /usr/local/lib/ruby/gems/2.5.0/gems/rails-0.8.0)
rake aborted!
LoadError: cannot load such file -- rake/rdoctask
/usr/local/lib/ruby/gems/2.5.0/gems/rails-0.8.0/Rakefile:3:in `<top (required)>'
/usr/local/lib/ruby/gems/2.5.0/gems/rake-12.3.2/exe/rake:27:in `<top (required)>'
(See full trace by running task with --trace)
~/rubymac$

我做宝石列表，看看我有哪些rails版本

~/rubymac$ gem list | grep "^rails ("
rails (5.2.2.1, 5.2.2, 5.2.1.1, 5.2.1, 5.2.0, 5.1.6, 5.1.4, 5.0.7.2, 5.0.7.1, 5.0.1, 5.0.0, 0.8.0)
~/rubymac$

我尝试卸载rails 0.8.0。它还促使我删除可执行文件，我说是的

~/rubymac$ gem uninstall rails -v0.8.0
Remove executables:
    rails

in addition to the gem? [Yn]  y               
Removing rails
Successfully uninstalled rails-0.8.0
~/rubymac$ gem list | grep "^rails ("
rails (5.2.2.1, 5.2.2, 5.2.1.1, 5.2.1, 5.2.0, 5.1.6, 5.1.4, 5.0.7.2, 5.0.7.1, 5.0.1, 5.0.0)
~/rubymac$ rails -v
-bash: /usr/local/bin/rails: No such file or directory
~/rubymac$ gem install rails -v5.2.2.1
Successfully installed rails-5.2.2.1
Parsing documentation for rails-5.2.2.1
Done installing documentation for rails after 0 seconds
1 gem installed

但也许我已经走了太远，说是先删除可执行文件，因为现在我得到'..rails：没有这样的文件或目录'

~/rubymac$ rails -v
-bash: /usr/local/bin/rails: No such file or directory
~/rubymac$

甚至在尝试安装5.2.2.1之后

~/rubymac$ gem install rails -v5.2.2.1
Successfully installed rails-5.2.2.1
Parsing documentation for rails-5.2.2.1
Done installing documentation for rails after 0 seconds
1 gem installed
~/rubymac$ rails -v
-bash: /usr/local/bin/rails: No such file or directory
~/rubymac$

添加

然后我尝试了gem uninstall rails，我卸载了所有版本。然后我做了sudo gem install rails。我开了一个新的终端窗口。 rails -v

当我做which rails它说/usr/bin/rails这是一个改进。

但是当我做轨道时 - 它说

Rails is not currently installed on this system. To get the latest version, simply type:

    $ sudo gem install rails

You can then rerun your "rails" command.
~$ 


~$ gem list | grep rails
coffee-rails (4.2.2, 4.2.1)
jquery-rails (4.3.1, 4.1.1)
rails (5.2.2.1)
rails-controller-testing (0.1.1)
rails-dom-testing (2.0.3, 2.0.2)
rails-html-sanitizer (1.0.4, 1.0.3)
sass-rails (5.0.7, 5.0.6)
sprockets-rails (3.2.1, 3.2.0)

实际上grep rail *更好'cos包括Uninstall Rails completely提到的铁路

另外，我没有使用任何版本控制管理器，没有rvm或rbenv

Answer 1

另一答案