$ git clone -n https://github.com/xcp-ng-rpms/libtalloc /var/lib/mock/v8.3-u-pcoval1-11071-29506/root/chroot_tmpdir/scmroot/libtalloc
Cloning into '/var/lib/mock/v8.3-u-pcoval1-11071-29506/root/chroot_tmpdir/scmroot/libtalloc'...
$ git fetch origin 68b1dea6868d67a3f2fa5057479cea27099b7619:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/libtalloc
 * [new ref]         68b1dea6868d67a3f2fa5057479cea27099b7619 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 68b1dea bump release for test build