$ git clone -n https://src.fedoraproject.org/rpms/rust-rustc-serialize.git /var/lib/mock/f38-build-side-43-rust-devel-1410799-31421/root/chroot_tmpdir/scmroot/rust-rustc-serialize
Cloning into '/var/lib/mock/f38-build-side-43-rust-devel-1410799-31421/root/chroot_tmpdir/scmroot/rust-rustc-serialize'...
$ git fetch origin f255d11df21bd4f6100aeead0cce89d194091932:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-rustc-serialize
 * [new ref]         f255d11df21bd4f6100aeead0cce89d194091932 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f255d11 Rebuilt for https://fedoraproject.org/wiki/Fedora_38_Mass_Rebuild