I upgraded to El Capitan, with Homebrew & Ruby, and this is how I did it flawlessly.

… and Xcode and Java, etc.

Prepare

If you don’t already have homebrew installed, do that first, so you don’t have to deal with SIP issues. Install all Software Updates available in the Apple Menu, up to and including El Capitan.

Hardware

After the installs and forced reboots my 27" Thunderbolt display wouldn’t display anything. Unplug, replug didn’t help. One more reboot fixed it.

Software

In order…

Xcode

The El Capitan install wiped out my Xcode install, so I had to search for it in the App Store and reinstall. I now believe that I deleted Xcode awhile ago and forgot, hence the reinstall. I did this on a machine that I rarely use.

After Xcode is finished installing, open iTerm, which I use as a Terminal.app replacement, or Terminal.app if you are so inclined.

∴ xcode-select --install
xcode-select: note: install requested for command line developer tools

A dialog opened, I chose “Install”, which finished in about a minute.

Java

Next, run java, which prompts with a dialog that has a button “More Info” which takes you to a website where you can accept the license and download the Java .dmg file. You need the JDK, not the JRE, if you intend to run java command-line based tools.

Unable to find any JVMs matching version "1.7".
No Java runtime present, try --request to install.
∴ java
No Java runtime present, requesting install.

Once downloaded, open the .dmg (for me it was jdk-8u60-macosx-x64.dmg) and install, then restart iTerm.

∴ java -version
java version "1.8.0_60"
Java(TM) SE Runtime Environment (build 1.8.0_60-b27)
Java HotSpot(TM) 64-Bit Server VM (build 25.60-b23, mixed mode)

Apps like RubyMine should work now, well, at least launch.

Homebrew

The doctor informed me of several warnings which I took care of as instructed.

∴ brew doctor
∴ sudo chown -R $(whoami):admin /usr/local
∴ cd /usr/local/Library && git stash && git clean -d -f
∴ cd ~
∴ brew prune
∴ brew unlink qt5

Then I was able to update Homebrew.

∴ brew update

qt5

I know the capybara-webkit gem will require qt5, and I know qt is one of the primary remaining pain points in homebrew / El Capitan issues tracker, so I decided to get it out of the way first.

∴ brew uninstall qt5
∴ brew install qt5
∴ brew linkapps qt5
∴ brew link --force qt5

That last line is required to make qmake available. Check with which qmake. Otherwise you will end up with this on the Capybara install later on:

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    /Users/pboling/.rvm/rubies/ruby-2.1.2/bin/ruby -r ./siteconf20150930-48087-1vw6bye.rb extconf.rb
sh: qmake: command not found
*** extconf.rb failed ***

GPG

Some software is now being signed with GPG, like RVM, for example, so install it.

brew install gpg

RVM

My Ruby was working, but I was having trouble with some native gem installations, so I decided to start fresh with a Ruby compiled against all the new homebrew and Xcode libraries.

rvm implode

Implode actually failed to remove the main ~/.rvm directory due to permissions issues. I had to sudo remove it.

sudo rm -rf /Users/pboling/.rvm

Follow the instructions here for installing RVM, I installed the development version, hoping it would have more El Capitan fixes in it:

gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
\curl -sSL https://get.rvm.io | bash

The main app I currently work on is using Ruby 2.1.2, so I install that first, and then go to the project directory to have the gemset created and to bundle.

Update 12/21/2015

I eventually ran into OpenSSL errors due to a certificate chain being outdated. The error was:

SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed:

I took a few additional steps to ensure Ruby would be fully operational, including disabling the binary install.

∴ rvm osx-ssl-certs update all
# or whichever Ruby you need
∴ rvm reinstall 2.2.3 --disable-binary 
∴ rvm use 2.2.3@myproject

Bundler version 1.9.7 because that’s what Heroku is on, and I want to stay in sync, because 1.10* changed things that make the Gemfile.lock incompatible with 1.9.7 on the deployed server (for me, with multiple gem sources, private gem server, etc).

∴ cd ~/project
# If you use a specific gemset
∴ gem install bundler -v 1.9.7 
∴ bundle install

Postgres

I also took the opportunity to upgrade to the latest Postgres.app. Alternatively you can install postgres with brew install postgres. I choose Postgres.app because it is supported directly by Heroku, and I like to think there is a parity win there somewhere.

Glorious.

Hero image (cropped) by Robby McCullough