Unable to copy from /usr/local/emq-relx/rel/conf/plugins to /usr/local/emq-relx/_rel/emqttd/etc because of {copy_failed, enoent}

[denghuimin]

hello:
my platform is centos 6.8 ,erlang19.3
when i install it from source files ,it's logs as following ,what's the problem?how can i solve it ?

===> Starting relx build process ...
===> Resolving OTP Applications from directories:
/usr/local/emq-relx/deps
/usr/local/lib/erlang/lib
/usr/local/emq-relx/apps
/usr/local/emq-relx/_rel
===> Resolved emqttd-2.1.0
===> Including Erts from /usr/local/lib/erlang
===> release successfully created!
===> Unable to copy from /usr/local/emq-relx/rel/conf/plugins to /usr/local/emq-relx/_rel/emqttd/etc because of {copy_failed,
enoent}
Unable to read template file (/usr/local/emq-relx/rel/conf/emq.conf) for overlay due to: no such file or directory
Unable to copy from /usr/local/emq-relx/rel/conf/acl.conf to /usr/local/emq-relx/_rel/emqttd/etc/acl.conf because of {copy_failed,
enoent}
Unable to copy from /usr/local/emq-relx/rel/schema to /usr/local/emq-relx/_rel/emqttd/releases/2.1.0 because of {copy_failed,
enoent}