$ git clone -n https://src.fedoraproject.org/rpms/rust-downcast.git /var/lib/mock/f38-build-side-42-init-devel-1395656-31050/root/chroot_tmpdir/scmroot/rust-downcast
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1395656-31050/root/chroot_tmpdir/scmroot/rust-downcast'...
$ git fetch origin ab5693b74b0bf8d8fa8060171ab78a6a67d45ad9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-downcast
 * [new ref]         ab5693b74b0bf8d8fa8060171ab78a6a67d45ad9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ab5693b Rebuilt for https://fedoraproject.org/wiki/Fedora_38_Mass_Rebuild