$ git clone -n https://src.fedoraproject.org/rpms/R-cli.git /var/lib/mock/f38-build-side-42-init-devel-612896-26291/root/chroot_tmpdir/scmroot/R-cli
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-612896-26291/root/chroot_tmpdir/scmroot/R-cli'...
$ git fetch origin a8db5a2aa3e2c1d57535ed1cb2ec0224090b31b3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-cli
 * [new ref]         a8db5a2aa3e2c1d57535ed1cb2ec0224090b31b3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a8db5a2 update to 3.6.0