$ git clone -n https://src.fedoraproject.org/rpms/rust-rocket.git /var/lib/mock/f45-build-44467-813/root/chroot_tmpdir/scmroot/rust-rocket
Cloning into '/var/lib/mock/f45-build-44467-813/root/chroot_tmpdir/scmroot/rust-rocket'...
$ git fetch origin e32f1f70dec73346c5b4d418e2d9506cf65d50e7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-rocket
 * [new ref]         e32f1f70dec73346c5b4d418e2d9506cf65d50e7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e32f1f7 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild