$ git clone -n https://src.fedoraproject.org/rpms/rust-sys-mount.git /var/lib/mock/f45-build-45308-822/root/chroot_tmpdir/scmroot/rust-sys-mount
Cloning into '/var/lib/mock/f45-build-45308-822/root/chroot_tmpdir/scmroot/rust-sys-mount'...
$ git fetch origin 07d8e3c72f0af96f916808b7a222bef7fefb0af2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-sys-mount
 * [new ref]         07d8e3c72f0af96f916808b7a222bef7fefb0af2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 07d8e3c Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild