gitlab-ce v13.1.1-ce svn commit fails as titled,
"level=fatal msg="error when getting repository: GITALY_REPO not found" in /var/log/gitlab/gitaly/gitaly_hooks.log

git push environment includes GITALY_REPO variable:
GITALY_REPO={"storageName":"default","relativePath":"@hashed/d4/73/d4735e3a265e16eee03f59718b9b5d03019c07d8b6c51f90da3a666eec13ab35.git","glRepository":"project-2","glProjectPath":"root/testproject"}