$ git clone -n https://src.fedoraproject.org/rpms/rust-zstd-sys.git /var/lib/mock/f40-build-2164085-50969/root/chroot_tmpdir/scmroot/rust-zstd-sys
Cloning into '/var/lib/mock/f40-build-2164085-50969/root/chroot_tmpdir/scmroot/rust-zstd-sys'...
$ git fetch origin ddda346ab3e1a3e6d37c9e9f46a3fbaef044a5b6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-zstd-sys
 * [new ref]         ddda346ab3e1a3e6d37c9e9f46a3fbaef044a5b6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ddda346 Update to version 2.0.8+zstd.1.5.5; Fixes RHBZ#2184801