$ git clone -n https://github.com/xcp-ng-rpms/zlib /var/lib/mock/v8.3-u-pcoval1-11020-29454/root/chroot_tmpdir/scmroot/zlib
Cloning into '/var/lib/mock/v8.3-u-pcoval1-11020-29454/root/chroot_tmpdir/scmroot/zlib'...
$ git fetch origin 727fe6875c56ee3f2ed3b4a4dd9045a29f11bb27:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/zlib
 * [new ref]         727fe6875c56ee3f2ed3b4a4dd9045a29f11bb27 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 727fe68 bump release for test build