Trouble with downloading Ruby

So I am trying to download Ruby from this site —

Managed to download Mac OSX 10.7 and 10.8 , but when I tried to open it, this is the message I got :

“RailsInstaller-1.0.4-osx-10.7” can’t be opened because it is from an unidentified developer.

Your security preferences allow installation of only apps from the Mac App Store and identified developers.

Safari downloaded this file today at 10:34 pm

Any idea how to fix this ?

  1. Open the System Preferences. This can be done by either clicking on the System Preferences icon in the Dock or by going to Apple Menu > System Preferences.

  2. Open the Security & Privacy pane by clicking Security & Privacy.

  3. Make sure that the General tab is selected. Click the icon labeled Click the lock to make changes.

  4. Enter your username and password into the prompt that appears and click Unlock.

  5. Under the section labeled Allow applications downloaded from:, select Anywhere. On the prompt that appears, click Allow From Anywhere.

  6. Exit System Preferences by clicking the red button in the upper left of the window. You should now be able to install applications downloaded from the internet.

  7. After you have been able to install… IMO, I would advise you repeat the procedure and restore the settings… Its for security reasons to prevent your MAC from being exposed to malicious softwares

Sure. Control-click on the installer icon, and choose "Open" from the contextual submenu. You will see a button in the resulting dialog that allows you to override Gatekeeper.


It looks like railsinstaller for mac is downloading a ruby version that is way out of date. Depending on the version of Mac OS you have currently, you couldbe seriously downgrading it.

I suggest following this set of instructions instead:

and when you get to the rails installation part, install version 5.0.1 instead the version listed.

Hi Cai,

Its advisable to use a version manager to manage ruby and gem versions. You can refer to - it has nice documentation and allows you to install specific versions of ruby that you are interested in.

I myself use MacBook Pro and never had issues with rvm.

Hands-on Solution Architect (RoR)
skype: goravbhootra

Use Docker. Go to my web site Ruby on Racetracks at, click on Installation, and click on “Getting Started”. You can have Ruby on Rails ready to roll in minutes, not hours. You can also reset the Docker container to its original conditions in just a few seconds.

I make sure that my rbenv-general Docker images include the latest versions of Ruby and Rails and the versions currently used in Rails Tutorial.

In my opinion, the main reason for having Ruby on Rails directly in the host OS is to be on the same page as teammates who rely on this setup. Because it takes hours of babysitting processes to set this up and because you can’t reset this development environment willy-nilly (as you can under the Docker way), I will NOT rely on Ruby on Rails in the host OS as my primary setup.