$ git clone -n https://src.fedoraproject.org/rpms/xsane.git /var/lib/mock/f45-build-39140-732/root/chroot_tmpdir/scmroot/xsane
Cloning into '/var/lib/mock/f45-build-39140-732/root/chroot_tmpdir/scmroot/xsane'...
$ git fetch origin 8c676a182b1540754a93c2fb8d405444554ad0d2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xsane
 * [new ref]         8c676a182b1540754a93c2fb8d405444554ad0d2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8c676a1 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild