Install CocoaPods on OSX-Mavericks (DP8)

Today I tried to upgrade CocoaPods in order to prepare my APPs to the upcoming changes in iOS7. Unfortunately I got an error

ERROR:  Error installing cocoapods:

ERROR: Failed to build gem native extension.

    /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby extconf.rb

I'm currently using "xCode5 GM" which is using the "OSX 10.8 SDK" which apparently is delivered without ruby version 2.0.

The solution was to download "xCode5 DP6" (containing the SDK 10.9), switch the command line tools to the version supplied by this release ("xcode-select") and run the following commands as a shell script

sys_rb_usr=/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr

sdk_rb_usr=`xcode-select -p`/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr

sudo cp -r $sdk_rb_usr/include $sys_rb_usr/include

And then update CocoaPods.