How do I upgrade Rails?

Question

I am new to Ruby and Rails, as well as all this command line melarky. So please bear with me.

I have installed, RubyGems, Homebrew, RVM, Rails etc, by following various tutorials.

I think I have all of this going now, but when I type:

rails --version

I get, 3.2.12. I notice that Rails 4 is out. How do I upgrade to this version?

If I do:

gem install rails

Even doing:

gem update rails

I still get 3.2.12.

Any ideas?

UPDATE

When trying a few options here, I get this message returned...

Michaels-MacBook-Pro:~ ParanoidAndroid$ gem install rails --version=4.0
Building native extensions.  This could take a while...
ERROR:  Error installing rails:
    ERROR: Failed to build gem native extension.

    /usr/local/rvm/rubies/ruby-1.9.3-p392/bin/ruby extconf.rb
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.

Provided configuration options:
    --with-opt-dir
    --without-opt-dir
    --with-opt-include
    --without-opt-include=${opt-dir}/include
    --with-opt-lib
    --without-opt-lib=${opt-dir}/lib
    --with-make-prog
    --without-make-prog
    --srcdir=.
    --curdir
    --ruby=/usr/local/rvm/rubies/ruby-1.9.3-p392/bin/ruby
    --with-atomic_reference-dir
    --without-atomic_reference-dir
    --with-atomic_reference-include
    --without-atomic_reference-include=${atomic_reference-dir}/include
    --with-atomic_reference-lib
    --without-atomic_reference-lib=${atomic_reference-dir}/lib
/usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:381:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
    from /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:461:in `try_link0'
    from /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:712:in `try_run'
    from extconf.rb:26:in `<main>'


Gem files will remain installed in /usr/local/rvm/gems/ruby-1.9.3-p392/gems/atomic-1.1.14 for inspection.
Results logged to /usr/local/rvm/gems/ruby-1.9.3-p392/gems/atomic-1.1.14/ext/gem_make.out

Seems there's an error happening. Any further ideas?

Thanks again everyone!

score 27 · Answer 1 · answered Feb 01 '18 at 12:52

27

If you already have a Rails project you should:

Specify the desired version in your Gemfile (e.g. gem 'rails', '~> 5.2.0.rc1')
Run bundle install (bundle update may be needed)
Run rails app:update (rake rails:update for 4.2 and earlier)
Follow instructions on screen
Follow the official guide for additional steps depending on your version

answered Feb 01 '18 at 12:52

thisismydesign

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A great guide. It just worked for Rails 5.1 to 5.2 migration. Just one note that I have got ````require': cannot load such file -- bootsnap/setup``` error so added `gem 'bootsnap'` to `Gemfile` to fix it. – laimison Jul 31 '19 at 20:02

score 13 · Accepted Answer · edited Jun 13 '19 at 21:17

13

If you are using RVM then you should create a seperate gemset first like:

rvm gemset create whateverName

in this example I will install rails 4

rvm install 2.0.0

rvm list  

rvm 2.0.0

^^^^(you may need to copy and paste the version number exactly here as it was displayed in rvm list)

rvm gemset create rails4

rvm gemset use rails4

add the following to your gemfile for existing apps

gem 'rails', '4.0.0'

then run

bundle update rails

or do following to just install the gem

gem install rails --version=4.0

UPDATE

If you havne't installed Xcode 4.5 CLI tools then you will need to

Preferences > Downloads > Components

DMG

https://developer.apple.com/downloads

you may then also need to use homebrew to update gcc

brew install apple-gcc42

the following link has all the information you will need:

https://thoughtbot.com/blog/the-hitchhikers-guide-to-riding-a-mountain-lion

edited Jun 13 '19 at 21:17

Dave Powers

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answered Dec 20 '13 at 12:58

Purple Hexagon

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Thanks for this, I tried it and got an error. Could you see my update above? – Michael Giovanni Pumo Dec 20 '13 at 13:11
Please see http://stackoverflow.com/questions/11802918/error-failed-to-build-gem-native-extension-when-installing-rails-on-mac-mountia/13176057#13176057 – Purple Hexagon Dec 20 '13 at 13:28
When I get XCode open, there is no such CLI Tools in the components. I downloaded XCode 5.0.2. I m using Mac Mavericks. – Michael Giovanni Pumo Dec 20 '13 at 13:57
seems the command line tools aren't offered after Xcode 5.0.1, maybe try... running the following command from the terminal: sudo xcode-select -switch /Applications/Xcode.app/Contents/Developer – Purple Hexagon Dec 20 '13 at 14:02
probably worth just trying brew install apple-gcc42 command as I should think that will fix the issue – Purple Hexagon Dec 20 '13 at 14:04
1

Thanks! brew install apple-gcc42 did the trick. Seems XCode doesn't have CLTools after version 4.2 – Michael Giovanni Pumo Dec 20 '13 at 14:14

score 5 · Answer 3 · answered Dec 20 '13 at 12:04

gem update rails does nothing for you, because bundler makes sure that only the gems specified in your Gemfile are loaded and used.

So in order to upgrade to Rails 4, you need to change the Rails version number in your Gemfile and run bundle update rails.

This Railscast guides you through all the steps of manually updating an existing application from Rails 3.2 to Rails 4:

http://railscasts.com/episodes/415-upgrading-to-rails-4

score 3 · Answer 4 · answered Dec 20 '13 at 12:08

3

You can install either with specific version OR putting gem version in itself Gemfile.

gem install rails -v 4.0.0

answered Dec 20 '13 at 12:08

Pravin Mishra

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score 1 · Answer 5 · answered Dec 20 '13 at 12:05

1

You can get a list of all gem versions with

gem list rails --remote --all

To install specify version 4.0.1 for example you can use

gem install rails -v 4.0.1

Or you could just specify the version in your Gemfile

answered Dec 20 '13 at 12:05

juco

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score 0 · Answer 6 · answered May 01 '19 at 22:07

0

Best to use gem list --remote --all. Unless your looking for that particular version as long as the gemset for that project has been established

answered May 01 '19 at 22:07

k clark

1
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How do I upgrade Rails?

6 Answers6

UPDATE