Rebulding

Today, CLD is constantly rebuilding the same files

Rebuilding dependent modules
 * Updating preserved libraries ...                                                                   [ ok ]
 * (1 of 4) Network utility to retrieve files from the WWW
 * Emerging net-misc/wget-1.20.1 ...                                                                  [ ok ]
 * (2 of 4) A Client that groks URLs
 * Emerging net-misc/curl-7.62.0 ...                                                                  [ ok ]
 * (3 of 4) A TLS 1.2 and SSL 3.0 implementation for the GNU project
 * Emerging net-libs/gnutls-3.5.19 ...                                                                [ ok ]
 * Installing net-libs/gnutls-3.5.19 ...                                                              [ ok ]
 * Installing net-misc/curl-7.62.0 ...                                                                [ ok ]
 * Installing net-misc/wget-1.20.1 ...                                                                [ ok ]
 * (4 of 4) The RDF Parser Toolkit
 * Emerging media-libs/raptor-2.0.15-r1 ...                                                           [ ok ]
 * Installing media-libs/raptor-2.0.15-r1 ...                                                         [ ok ]
 * Updating configuration files ...                                                                   [ ok ]
 * System update finished!

*I do not know how to solve the problem. How to find out which is the wrong symbolic link. What is the purpose of zz-files on portage directories
*
# emerge @preserved-rebuild raptor

Local copy of remote index is up-to-date and will be used.
Calculating dependencies… done!
[binary R ] net-misc/wget-1.20.1
[binary R ] media-libs/raptor-2.0.15-r1

Emerging binary (1 of 2) net-misc/wget-1.20.1::gentoo
Emerging binary (2 of 2) media-libs/raptor-2.0.15-r1::gentoo
Installing (2 of 2) media-libs/raptor-2.0.15-r1::gentoo
Installing (1 of 2) net-misc/wget-1.20.1::gentoo
Jobs: 2 of 2 complete Load avg: 1.24, 1.12, 0.54

* Messages for package media-libs/raptor-2.0.15-r1:

* One or more symlinks to directories have been preserved in order to
* ensure that files installed via these symlinks remain accessible. This
* indicates that the mentioned symlink(s) may be obsolete remnants of an
* old install, and it may be appropriate to replace a given symlink with
* the directory that it points to.
*
* /usr/share/gtk-doc/html/raptor2
*

Auto-cleaning packages…

No outdated packages were found on your system.

* Regenerating GNU info directory index…
* Processed 120 info files.

!!! existing preserved libs:

package: net-dns/libidn2-2.1.0
* - /usr/lib64/libidn2.so.0
* - /usr/lib64/libidn2.so.0.3.4
* used by /usr/bin/wget (net-misc/wget-1.20.1)
* used by /usr/lib64/libraptor2.so.0.0.0 (media-libs/raptor-2.0.15-r1)
Use emerge @preserved-rebuild to rebuild packages using these libraries
^^
The message that the system writes is nonsense because it was at the beginning that command was done