$ git clone -n https://src.fedoraproject.org/rpms/emacs-magit.git /var/lib/mock/f45-build-8172-378/root/chroot_tmpdir/scmroot/emacs-magit
Cloning into '/var/lib/mock/f45-build-8172-378/root/chroot_tmpdir/scmroot/emacs-magit'...
$ git fetch origin d399f9f7a901c0a6692e633fe3a2f3e748b57ecc:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/emacs-magit
 * [new ref]         d399f9f7a901c0a6692e633fe3a2f3e748b57ecc -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d399f9f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild