$ git clone -n https://src.fedoraproject.org/rpms/log4cxx.git /var/lib/mock/f45-build-17538-501/root/chroot_tmpdir/scmroot/log4cxx
Cloning into '/var/lib/mock/f45-build-17538-501/root/chroot_tmpdir/scmroot/log4cxx'...
$ git fetch origin e9f686f7a4150d320abbc150bfa07cb011721f1b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/log4cxx
 * [new ref]         e9f686f7a4150d320abbc150bfa07cb011721f1b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e9f686f Update to 1.8.0