$ git clone -n https://src.fedoraproject.org/rpms/rust-rav1e.git /var/lib/mock/f38-build-side-42-init-devel-1391766-30858/root/chroot_tmpdir/scmroot/rust-rav1e
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1391766-30858/root/chroot_tmpdir/scmroot/rust-rav1e'...
$ git fetch origin 9742af361136463ac62213d234653b9ddd298078:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-rav1e
 * [new ref]         9742af361136463ac62213d234653b9ddd298078 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9742af3 Update to version 0.6.6; Fixes RHBZ#2149770