$ git clone -n https://src.fedoraproject.org/rpms/ldc1.30.git /var/lib/mock/f38-build-718552-96739/root/chroot_tmpdir/scmroot/ldc1.30
Cloning into '/var/lib/mock/f38-build-718552-96739/root/chroot_tmpdir/scmroot/ldc1.30'...
$ git fetch origin 398dc6475fdabef0c9489e326d369d2aad4309b3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ldc1.30
 * [new ref]         398dc6475fdabef0c9489e326d369d2aad4309b3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 398dc64 Initial Fedora packaging