$ git clone -n https://src.fedoraproject.org/rpms/subversion.git /var/lib/mock/f39-build-1624658-39084/root/chroot_tmpdir/scmroot/subversion
Cloning into '/var/lib/mock/f39-build-1624658-39084/root/chroot_tmpdir/scmroot/subversion'...
$ git fetch origin bff2e895c145928c97eccbe8ffbbeb5c97f26b9b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/subversion
 * [new ref]         bff2e895c145928c97eccbe8ffbbeb5c97f26b9b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bff2e89 - use %patch -P throughout