Hi,

Recently, after a update, I always see follow information after every 
emerge operation

!!! existing preserved libs:
 >>> package: dev-qt/qtxml-5.15.1
  *  - /usr/lib64/libQt5Xml.so.5
  *  - /usr/lib64/libQt5Xml.so.5.15.1
  *      used by /opt/kingsoft/wps-office/office6/librpcetapi_sysqt5.so 
(app-office/wps-office-11.1.0.9615)
  *      used by /opt/kingsoft/wps-office/office6/librpcwppapi_sysqt5.so 
(app-office/wps-office-11.1.0.9615)
  *      used by /opt/kingsoft/wps-office/office6/librpcwpsapi_sysqt5.so 
(app-office/wps-office-11.1.0.9615)
Use emerge @preserved-rebuild to rebuild packages using these libraries

I have used the command 'emerge @preserved-rebuild' to rebuild but it 
still appear as before.

And when rebuild, there is no warning info. Also, the wps-office is 
useable from the beginning to end.

I want to know what cause the strange problem. Could you please tell me 
the brief principle and solution?

Thanks.