Marshall::dumpadds encoding information and output differs from expected. Other seven errors were really funny.
Seven tests fail in CSS section of HTML output. Browsing through revision history brought me to [r332] and [r329], both commited by Upstream Developer around 22 Apr 2009. Patch was obvious and commited in my repo on 29 Jul 2009.
After several months I've decided to update ruby-coderay package. There was another amazing [r372] commited on 18 Oct 2009. And fixed with another obvious patch on 09 Nov 2009.
Since Aplil 2009 only one test was fixed by [r361] on 10 Oct 2009.
Bottom line: test suite for CodeRay project has been broken for almost eight months and nobody gives a fuck. Gosh, I LOVE Free Software!