$ git clone -n https://github.com/xcp-ng-rpms/libssh2.git /var/lib/mock/v8.3-u-pcoval2-10410-28971/root/chroot_tmpdir/scmroot/libssh2
Cloning into '/var/lib/mock/v8.3-u-pcoval2-10410-28971/root/chroot_tmpdir/scmroot/libssh2'...
$ git fetch origin e1a634be185eaf5e18f9cfbe7046f53f041e440d:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/libssh2
 * [new ref]         e1a634be185eaf5e18f9cfbe7046f53f041e440d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e1a634b bump release for test build