$ git clone -n https://src.fedoraproject.org/rpms/java-11-openjdk-portable.git /var/lib/mock/f39-build-2119045-50731/root/chroot_tmpdir/scmroot/java-11-openjdk-portable
Cloning into '/var/lib/mock/f39-build-2119045-50731/root/chroot_tmpdir/scmroot/java-11-openjdk-portable'...
$ git fetch origin b565c3ecaaf01ecf0562409a0d4e679d497e2490:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/java-11-openjdk-portable
 * [new ref]         b565c3ecaaf01ecf0562409a0d4e679d497e2490 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b565c3e packing generated sources