$ git clone -n https://src.fedoraproject.org/rpms/hello.git /var/lib/mock/f45-build-13394-450/root/chroot_tmpdir/scmroot/hello
Cloning into '/var/lib/mock/f45-build-13394-450/root/chroot_tmpdir/scmroot/hello'...
$ git fetch origin 2621a97179dd5182d127a98a50759a637a4fa334:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/hello
 * [new ref]         2621a97179dd5182d127a98a50759a637a4fa334 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2621a97 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild