$ git clone -n https://src.fedoraproject.org/rpms/extrema.git /var/lib/mock/f45-build-8567-391/root/chroot_tmpdir/scmroot/extrema
Cloning into '/var/lib/mock/f45-build-8567-391/root/chroot_tmpdir/scmroot/extrema'...
$ git fetch origin 45d58ea0452e7050bfe8ffb94f51e6a5c9e4f241:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/extrema
 * [new ref]         45d58ea0452e7050bfe8ffb94f51e6a5c9e4f241 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 45d58ea Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild