Unfortunately version 1.10 has been killed in https://github.com/freebsd/freebsd-ports/commit/78d03534d7899a27f3a74cb078ccc192a61113ff not taking into account that both 1.9 and 1.10 are LTS releases while 1.11 will only live for 6 months. Please readd 1.10 just like 1.9 is right now selectable via WITH_SUBVERSION_VER.
Are you ready to be maintainer of 1.10 port?
(In reply to Lev A. Serebryakov from comment #1) That would be OK for me, 1.10.x does not change that often and I do already mantain other ports too.
A commit references this bug: Author: lev Date: Thu Apr 25 16:28:48 UTC 2019 New revision: 500031 URL: https://svnweb.freebsd.org/changeset/ports/500031 Log: Add LTS version of subversion to ports. PR: 235934 Changes: head/devel/Makefile head/devel/p5-subversion/Makefile head/devel/py-subversion/Makefile head/devel/ruby-subversion/Makefile head/devel/subversion/Makefile.addons head/devel/subversion-lts/ head/devel/subversion-lts/Makefile head/devel/subversion-lts/Makefile.addons head/devel/subversion-lts/Makefile.common head/devel/subversion-lts/pkg-descr head/java/java-subversion/Makefile head/security/subversion-gnome-keyring/Makefile
I've added such port.