$ git clone -n https://src.fedoraproject.org/rpms/php-pecl-var-representation.git /var/lib/mock/f40-build-733827-105472/root/chroot_tmpdir/scmroot/php-pecl-var-representation
Cloning into '/var/lib/mock/f40-build-733827-105472/root/chroot_tmpdir/scmroot/php-pecl-var-representation'...
$ git fetch origin c94c125fcfc96ee14d45526f0a06c6d5f50e9dd4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/php-pecl-var-representation
 * [new ref]         c94c125fcfc96ee14d45526f0a06c6d5f50e9dd4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c94c125 build out of sources tree