As a part of the FreeBSD development lifecycle, files and their contents occasionally become obsolete. This may be because functionality is implemented elsewhere, the version number of the library has changed, or it was removed from the system entirely. This includes old files, libraries, and directories, which should be removed when updating the system. The benefit is that the system is not cluttered with old files which take up unnecessary space on the storage and backup media. Additionally, if the old library has a security or stability issue, the system should be updated to the newer library to keep it safe and to prevent crashes caused by the old library. Files, directories, and libraries which are considered obsolete are listed in /usr/src/ObsoleteFiles.inc. The following instructions should be used to remove obsolete files during the system upgrade process.

Follow the steps outlined in Section 25.7.1, “The Canonical Way to Update Your System”. After the make installworld and the subsequent mergemaster have finished successfully, check for obsolete files and libraries as follows:

If any obsolete files are found, they can be deleted using the following command:

A prompt is displayed before deleting each obsolete file. To skip the prompt and let the system remove these files automatically, use BATCH_DELETE_OLD_FILES:

The same goal can be achieved by piping these commands through yes:

Utilities for checking shared library dependencies are available from the Ports Collection in sysutils/libchk or sysutils/bsdadminscripts.

Obsolete shared libraries can conflict with newer libraries, causing messages like these:

To solve these problems, determine which port installed the library:

Then deinstall, rebuild and reinstall the port. ports-mgmt/portmaster can be used to automate this process. After all ports are rebuilt and no longer use the old libraries, delete the old libraries using the following command: