Installing Gem Fails with Permissions Error

How to install a gem or update RubyGems if it fails with a permissions error

You don't have write permissions into the /Library/Ruby/Gems/1.8 directory.

means exactly that, you don't have permission to write there.

That is the version of Ruby installed by Apple, for their own use. While it's OK to make minor modifications to that if you know what you're doing, because you are not sure about the permissions problem, I'd say it's not a good idea to continue along that track.

Instead, I'll strongly suggest you look into using either rbenv or RVM to manage a separate Ruby, installed into a sandbox in your home directory, that you can modify/fold/spindle/change without worrying about messing up the system Ruby.

Between the two, I use rbenv, though I used RVM a lot in the past. rbenv takes a more "hands-off" approach to managing your Ruby installation. RVM has a lot of features and is very powerful, but, as a result is more intrusive. In either case, READ the installation documentation for them a couple times before starting to install whichever you pick.

Getting permission denied error when I run gem install bundler

you are using the system's ruby and now you need to root level permission to to install bundler. Sudo enables root privileges. Check if your account has root privileges.

I prefer using a version and manager like rbenv. Install rbenv . then install the required version of ruby and then install bundler.

Permissions error with gem install

Use chmod on the directory something like this:

sudo chmod -R g+w /Library/Ruby/Gems/1.8

That might work.

gem install permission problem

For a systemwide Ruby install, become root. For example:

$ sudo gem install hpricot

However, the modern approach in many circumstances, including in development, is to use a tool that lets you easily install and use Ruby as a normal user. This lets you avoid having to become root. There are a few such tools, and the one I use is RVM.

# install rvm into your ~
$ \curl -sSL https://get.rvm.io | bash -s stable

# install latest version of ruby into your ~
$ rvm install ruby

# installs a gem into your ~
$ gem install $SOME_GEM_NAME

Is there a reliable way to avoid permission denied errors when installing Ruby gems with native extensions on Windows Subsystem for Linux?

The problem that I'm experiencing may be related to Visual Studio Code's file watching. It is reflected in two GitHub issues against WSL - 1956 and 3395. Visual Studio Code has remote.WSL.fileWatcher.polling, which can be enabled which works around this issue. However, the documentation states that there is a performance impact for large workspaces and it may be necessary to also adjust the remote.WSL.fileWatcher.pollingInterval setting. WSL2 will resolve these issues.

Since enabling this flag, I haven't seen the error while working with VS Code running.

Now that WSL2 is out, I was able to disable this flag and the issue has not reappeared. It appears that if you can upgrade to WSL2, that may be a preferred solution. However, for anyone who hasn't yet upgraded or can't upgrade, toggling the remote.WSL.fileWatcher.polling and remote.WSL.fileWatcher.pollingInterval should be good.