The space is not enough for mock_chroot_tmpfs to build xenserver

You can modify the file:

vi  /etc/mock/site-defaults.cfg

enable the plugin using this settings:

config_opts['plugin_conf']['tmpfs_enable'] = True
config_opts['plugin_conf']['tmpfs_opts'] = {}
config_opts['plugin_conf']['tmpfs_opts']['required_ram_mb'] = 1024
config_opts['plugin_conf']['tmpfs_opts']['max_fs_size'] = '768m'
config_opts['plugin_conf']['tmpfs_opts']['mode'] = '0755'
config_opts['plugin_conf']['tmpfs_opts']['keep_mounted'] = False

Note: change the size of 'max_fs_size':

config_opts['plugin_conf']['tmpfs_opts']['max_fs_size'] = '768m'

to

config_opts['plugin_conf']['tmpfs_opts']['max_fs_size'] = '2768m'

that's all~~~

hopefully it will be useful .