$ git clone -n https://src.fedoraproject.org/rpms/linux-sysinfo-snapshot.git /var/lib/mock/f45-build-17442-499/root/chroot_tmpdir/scmroot/linux-sysinfo-snapshot
Cloning into '/var/lib/mock/f45-build-17442-499/root/chroot_tmpdir/scmroot/linux-sysinfo-snapshot'...
$ git fetch origin 678313db9765a2545b7a1fa2857bab4bf64966f1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/linux-sysinfo-snapshot
 * [new ref]         678313db9765a2545b7a1fa2857bab4bf64966f1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 678313d Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild