Why does yum print to run makecache fast on stderr while running makecache fast ?

Issue

• Why does yum print to run makecache fast on stderr while running makecache fast ?
• See the commands below.

[root@rhel7 /]# yum -d 2 makecache fast >/tmp/yum_stdout 2>/tmp/yum_stderr
[root@rhel7 /]# grep . /tmp/yum_std*
/tmp/yum_stderr:Repodata is over 2 weeks old. Install yum-cron? Or run:  yum makecache fast
/tmp/yum_stdout:Loaded plugins: fastestmirror, product-id, search-disabled-repos, subscription-manager
/tmp/yum_stdout:This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
/tmp/yum_stdout:Determining fastest mirrors
/tmp/yum_stdout: * epel_server: islal008.in.audi.vwg:888
/tmp/yum_stdout: * rhs_server: islal008.in.audi.vwg:888
/tmp/yum_stdout: * rhs_server_debug: islal008.in.audi.vwg:888
/tmp/yum_stdout: * rhs_server_optional: islal008.in.audi.vwg:888
/tmp/yum_stdout: * rhs_server_thirdparty_oracle_java: islal008.in.audi.vwg:888
/tmp/yum_stdout:Metadata Cache Created