This weekend I was trying to do a fresh install of Mountain Lion. This link provides you instructions on how to create a bootable Mountain Lion install disk. If you are going to burn a DVD, you need to make sure you use DVD-DL as normal Mountain Lion won’t fit in the 4.3G DVD.
I use RVM so I installed Xcode and the Command Line Tools. Installing Ruby 1.9.3 with RVM works fine but when I tried to install Ruby 1.8.7, I got:
The autodetected CC(/usr/bin/gcc-4.2) is LLVM based, it is not yet fully supported by ruby and gems, please read `rvm requirements`, and set CC=/path/to/gcc .
The problem is that we need a non-LLVM based gcc compiler. After spending half an hour googling, there are tons of solutions but I found using this homebrew package is easiest:
brew install https://raw.github.com/Homebrew/homebrew-dupes/master/apple-gcc42.rb
You need to install homebrew if you haven’t. I highly recommend you install homebrew as it just makes installing Unix tools so much easier.
The next thing you need to install is XQuartz as X11 is no longer shipped with Mac OS X, so download XQuartz, and run the following to install Ruby 1.8.7:
export CPPFLAGS=-I/opt/X11/include rvm install 1.8.7
Bonus: MySQL gem 2.8.1
Installing MySQL 2.8.1 gem is just like what you did in Lion, after installing MySQL (I use the 64-bit DMG from MySQL download page), run:
export DYLD_LIBRARY_PATH="/usr/local/mysql/lib:$DYLD_LIBRARY_PATH" env ARCHFLAGS="-arch x86_64" gem install mysql -v='2.8.1' -- --with-mysql-dir=/usr/local/mysql --with-mysql-lib=/usr/local/mysql/lib --with-mysql-include=/usr/local/mysql/include --with-mysql-config=/usr/local/mysql/bin/mysql_config