$ git clone -n https://github.com/xcp-ng-rpms/krb5 /var/lib/mock/v8.3-incoming-10633-29186/root/chroot_tmpdir/scmroot/krb5
Cloning into '/var/lib/mock/v8.3-incoming-10633-29186/root/chroot_tmpdir/scmroot/krb5'...
$ git fetch origin b56cb5ffe1b3a2663a795fd6d5e829c9efe81375:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/krb5
 * [new ref]         b56cb5ffe1b3a2663a795fd6d5e829c9efe81375 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b56cb5f Merge pull request #1 from xcp-ng-rpms/XS-1570