$ git clone -n https://src.fedoraproject.org/rpms/rust-generic-array.git /var/lib/mock/f45-build-41856-786/root/chroot_tmpdir/scmroot/rust-generic-array
Cloning into '/var/lib/mock/f45-build-41856-786/root/chroot_tmpdir/scmroot/rust-generic-array'...
$ git fetch origin 5da5d38783f59b912a856f21c2d22d0ed4be4fcd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-generic-array
 * [new ref]         5da5d38783f59b912a856f21c2d22d0ed4be4fcd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5da5d38 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild