ecompress and ecompressdir shouldn't be used in ebuilds. See tracker bug 218347.
This is being addressed for 1.6.17-r2; my apologies for the long delay.
+*subversion-1.6.17-r2 (19 Aug 2011) + + 19 Aug 2011; Tony Vroon <chainsaw@gentoo.org> -files/80subversion-extras, + -subversion-1.6.17-r1.ebuild, +subversion-1.6.17-r2.ebuild: + More gracefully handle dependency between KDE & NLS USE-flags, as requested + by Jeroen Roovers in bug #330941. Perfection would require EAPI=4, which I + can not use yet. Tell user to restart daemon after upgrade, as requested by + Joel Koglin in bug #337042. Use recursive dodoc instead of ecompressdir as + requested by Ulrich Müller in bug #356503. Move the environment config back + to inline for now, as Kent Fredric reports that variable substitution broke + and caused env-update failures. Closes bug #379819. Killed old -r1 ebuild due + to this problem.