$ git clone -n https://src.fedoraproject.org/rpms/rust-heapsize.git /var/lib/mock/f45-build-42307-792/root/chroot_tmpdir/scmroot/rust-heapsize
Cloning into '/var/lib/mock/f45-build-42307-792/root/chroot_tmpdir/scmroot/rust-heapsize'...
$ git fetch origin fb4ce0ea61d29458caa5969a92e3a541b0e0a79d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-heapsize
 * [new ref]         fb4ce0ea61d29458caa5969a92e3a541b0e0a79d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fb4ce0e Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild