New ebuild including support for "gettid" error in previous compilation.
Created attachment 109111 [details, diff] Patch from the stepmania forums http://www.stepmania.com/boards/viewtopic.php?p=9722&sid=a1932ca6146b2a0e390a3e1a3e307f36
Created attachment 109113 [details] Ebuild to use the patch
Applied, thanks for reporting.