$ git clone -n https://src.fedoraproject.org/rpms/emacs-slime.git /var/lib/mock/f38-build-side-42-init-devel-1133745-30350/root/chroot_tmpdir/scmroot/emacs-slime
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1133745-30350/root/chroot_tmpdir/scmroot/emacs-slime'...
$ git fetch origin 91aeaa9ad495f751c4c972b90c259c30e2914189:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/emacs-slime
 * [new ref]         91aeaa9ad495f751c4c972b90c259c30e2914189 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 91aeaa9 - Update to 2.28, fixes FTBFS rhbz#2164770