$ git clone -n https://src.fedoraproject.org/rpms/plasma-vault.git /var/lib/mock/f42-build-side-1-3583190-46888/root/chroot_tmpdir/scmroot/plasma-vault
Cloning into '/var/lib/mock/f42-build-side-1-3583190-46888/root/chroot_tmpdir/scmroot/plasma-vault'...
$ git fetch origin 2deaad2f5a637aba8908690b1a696011e14f6eac:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-vault
 * [new ref]         2deaad2f5a637aba8908690b1a696011e14f6eac -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2deaad2 6.4.2