The ebuild is version 1.0.5 but github/nirvdrum/svn2git is at 2.2.1 and recommended by github themselves, so likely stable, too.
Hello R Stephan, there are at least two distinct projects by the name "svn2git": A) https://github.com/nirvdrum/svn2git - Wrapper around git-svn - Written in Ruby B) https://gitorious.org/svn2git/svn2git - Not a wrapper to git-svn - Written in C++ by KDE people - Also called "svn-all-fast-export", e.g. in Debian - Different to git-svn in major aspects I am therefore closing as "CANTFIX" for now, the way that seems to fit best to me. If you need that other svn2git in Gentoo, someone will have to find a new name to circumvent the collision in Gentoo.