[macos] You don't have write permissions for the /Library/Ruby/Gems/2.3.0 directory. (mac user)

below is what I need to do.

To run the specs, you'll need to install RSpec. First, run gem install bundler in the root directory of your project. Then, run bundle install. To run a single spec file, run a command like this: bundle exec rspec spec/00_hello_spec.rb. To run all of the specs at once, run bundle exec rspec.

So, I typed gem install bundler in Terminal, and got the error:

You don't have write permissions for the /Library/Ruby/Gems/2.3.0 directory.

and this was in the project file in atom

source "https://rubygems.org"
gem "rspec", "~> 3.2.0"

My question is:

It seems like terminal is giving me the response because I'm not supposed to change anything on ruby, and I need to bundle install inside of atom? Could anyone tell me how to use atom or run anything in atom?

If you don't want to run sudo then install ruby using homebrew

brew install ruby
export GEM_HOME="$HOME/.gem"
gem install rails

You may want to add export GEM_HOME="$HOME/.gem" to your ~/.bash_profile or .zshrc if you're using zsh

Note: RubyGems keeps old versions of gems, so feel free to do some cleaning after updating:

gem cleanup

I'm using Mojave with rbenv, this solution works for me:

$ vi ~/.bash_profile

Add this line into the file:

if which rbenv > /dev/null; then eval "$(rbenv init -)"; fi

It's generally recommended to use a version manager like rbenv or rvm. Otherwise, installed Gems will be available as root for other users.

If you know what you're doing, you can use sudo gem install.

TL;DR

In several occasions, I've solved this kind of errors by just closing my terminal session and opening a new one before retrying the failing command.

Long explanation

In some SOs (such as MacOS) there is already a pre-installed, system-wide version of ruby. If you are using a version manager, such as rbenv or asdf, they work by playing with the environment of your current session so that the relevant commands point to the binaries installed by the version manager.

When installing a new binary, the version manager installs it in a special location, usually somewhere under the user's home directory. It then configures everything in your PATH so that you get the freshly installed binaries when you issue a command, instead of the ones that came with your system. However, if you don't restart the session (there are other ways of getting your environment updated, but that's the easiest one) you don't get the new configuration and you will be using the original installation.

Run this

$ rbenv init
# Load rbenv automatically by appending
# the following to ~/.zshrc:

eval "$(rbenv init -)"

Follow instructions, (in my case add to ~/.zshrc) ;)

Also important: Changes only take effect if you reboot your console. Two options

• Enter source <modified file>
• close and open again

I have faced same issue after install macOS Catalina. I had try below command and its working.

sudo gem update

Simply doing sudo gem uninstall cocoapods worked for me.

If you have installed ruby separately and installed ruby using rbenv/rvm you budler might point to different versions.

try

gem env home

and

ruby -v

both should point to same version.check you have installed ruby using rbenv/rvm, If so delete the ruby version you installed separately.

In order for gem to work, you must invoke rbenv,

rbenv shell <ruby version> 

and

rbenv global <ruby version>

I am not sure how RVM works. Let me know if this works.

As @idleberg mentions, on Mac OS, it is best to install rbenv to avoid permissions errors when using manually installed ruby.

Installation

$ brew update
$ brew install rbenv

Add the following in .bashrc file:

eval "$(rbenv init -)"

Now, we can look at the list of ruby versions available for install

$ rbenv install -l

Install version 2.3.8 for example

$ rbenv install 2.3.8

Now we can use this ruby version globally

$ rbenv global 2.3.8

Finally run

$ rbenv rehash

$ which ruby
/Users/myuser/.rbenv/shims/ruby
$ ruby -v
ruby 2.3.7p456 (2018-03-28 revision 63024) [x86_64-darwin17]

Go for it

Now install bundler

$ gem install bundler

All done!

Solution for MAC. run the command

sudo gem update    

then type your Mac password when prompted

Worked for me using the parameter --user-install running following command:

gem install name_of_gem --user-install

Then he started to fetch and install it.

Edit

There was one gem I still could not install (it required the Ruby.h headers of the Ruby development kit or something), then I tried the different version managers, but somehow that still did not really work as it was stated in the documentations how to just install and switch (it did just not switch the versions). Then I removed all the installed version managers and installed afterwards with brew install ruby the latest version and did set the PATH variable, too. (It will be mentioned after the installation of ruby from brew), which worked.

Solution for Mac

1. Install/update RVM with last ruby version

   \curl -sSL https://get.rvm.io | bash -s stable

2. Install bundler

   gem install bundler

after this two commands (sudo) gem install .... started to work

Update: I've since written a very detailed explanation of the various ways you can install Ruby gems on a Mac. My original recommendation to use a script still stands, but my article goes into more detail: https://www.moncefbelyamani.com/the-definitive-guide-to-installing-ruby-gems-on-a-mac/

You are correct that macOS won't let you change anything with the Ruby version that comes installed with your Mac. However, it's possible to install gems like bundler using a separate version of Ruby that doesn't interfere with the one provided by Apple.

Using sudo to install gems, or changing permissions of system files and directories is strongly discouraged, even if you know what you are doing. Can we please stop providing this bad advice? Here's a detailed article I wrote showing how sudo gem install can wipe out your computer: https://www.moncefbelyamani.com/why-you-should-never-use-sudo-to-install-ruby-gems/

The solution involves two main steps:

1. Install a separate version of Ruby that does not interfere with the one that came with your Mac.
2. Update your PATH such that the location of the new Ruby version is first in the PATH. Some tools do this automatically for you. If you're not familiar with the PATH and how it works, read my guide.

There are several ways to install Ruby on a Mac. The best way that I recommend, and that I wish was more prevalent in the various installation instructions out there, is to use an automated script that will set up a proper Ruby environment for you. This drastically reduces the chances of running into an error due to inadequate instructions that make the user do a bunch of stuff manually and leaving it up to them to figure out all the necessary steps.

The other route you can take is to spend extra time doing everything manually and hoping for the best. First, you will want to install Homebrew, which installs the prerequisite command line tools, and makes it easy to install other necessary tools.

Then, the two easiest ways to install a separate version of Ruby are:

If you would like the flexibility of easily switching between many Ruby versions [RECOMMENDED]

Choose one of these four options:

• chruby and ruby-install - my personal recommendations and the ones that are automatically installed by my script. These can be installed with Homebrew:

brew install chruby ruby-install

• rbenv - can be installed with Homebrew

• RVM

• asdf

If you chose chruby and ruby-install, you can then install the latest Ruby like this:

ruby-install ruby

Once you've installed everything and configured your .zshrc or .bash_profile according to the instructions from the tools above, quit and restart Terminal, then switch to the version of Ruby that you want. In the case of chruby, it would be something like this:

chruby 2.7.2

Whether you need to configure .zshrc or .bash_profile depends on which shell you are using. If you're not sure, read this guide: https://www.moncefbelyamani.com/which-shell-am-i-using-how-can-i-switch/

If you know for sure you don't need more than one version of Ruby at the same time (besides the one that came with macOS)

• Install ruby with Homebrew:

brew install ruby

Then update your PATH by running (replace 2.7.0 with your newly installed version):

echo 'export PATH="/usr/local/opt/ruby/bin:/usr/local/lib/ruby/gems/2.7.0/bin:$PATH"' >> ~/.zshrc

Then "refresh" your shell for these changes to take effect:

source ~/.zshrc

Or you can open a new terminal tab, or quit and restart Terminal.

Replace .zshrc with .bash_profile if you are using Bash. If you're not sure which shell you are using, read this guide: https://www.moncefbelyamani.com/which-shell-am-i-using-how-can-i-switch/

To check that you're now using the non-system version of Ruby, you can run the following commands:

which ruby

It should be something other than /usr/bin/ruby

ruby -v

It should be something other than 2.6.3 if you're on macOS Catalina. As of today, 2.7.2 is the latest Ruby version.

Once you have this new version of Ruby installed, you can now install bundler (or any other gem):

gem install bundler

A different installation of ruby should be used. I use rbenv for that purpose.

# install your version of ruby
$ rbenv install 2.0.0-p247

# modify .ruby_version on current directory
$ rbenv local 2.0.0-p247

# proceed installing gems
$ gem install bundler

Disclamer: I am not a ruby person. This worked for me and if you are a ruby expert and see things to change in this answer, please, go ahead or comment!

Try this:

sudo gem install cocoapods --user-install

Worked for me

This worked for me on Mac

sudo chown -R $(whoami) $(brew --prefix)/*