$ git clone -n https://github.com/xcp-ng-rpms/tcpdump.git /var/lib/mock/v8.3-u-pcoval2-10576-29130/root/chroot_tmpdir/scmroot/tcpdump
Cloning into '/var/lib/mock/v8.3-u-pcoval2-10576-29130/root/chroot_tmpdir/scmroot/tcpdump'...
$ git fetch origin c7e243b6efe9cfdafef8d9d1184729cded63640b:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/tcpdump
 * [new ref]         c7e243b6efe9cfdafef8d9d1184729cded63640b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c7e243b bump release for test build