This comes from:
svn diff ^/nixpkgs/trunk/@18255 ^/nixpkgs/branches/stdenv-updates/ > diff
patch -p0 < diff
and then adding into svn all files new from the patch.
trunk@18255 comes from the last time I updated stdenv-updates from trunk.
svn path=/nixpkgs/stdenv-updates2/; revision=18272