On http://gcc.gnu.org/wiki/SvnMerge I changed: $ svn switch svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4.0-branch to: $ svn switch svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_0-branch :-( Took me a while to figure out what was wrong. :-( The error message is, uhm, well, unfortunate. If the doc was correct, someone will have to rename some things and switch it back.