The make buildworld command is used to build the FreeBSD operating system from the source code. It is typically used to update the system to a newer version or to rebuild the system after making changes to the source code.
If you encounter the error cd: can't cd to /usr/src/tools/build/make_check when running the make buildworld command, it may be because the /usr/src/tools/build/make_check directory does not exist or is not accessible.
To fix this error, you can try the following solutions:
Make sure that the source code for the FreeBSD operating system is installed on the system. The make buildworld command requires the source code to be present in the /usr/src directory.
Check the permissions on the /usr/src/tools/build/make_check directory. Make sure that the directory is readable and executable by the user running the make buildworld command.
Check the /etc/make.conf file and make sure that the MAKE_CHECK_TARGET variable is set to check or buildcheck. If the variable is set to something else, it may cause the make buildworld command to fail.
If the /usr/src/tools/build/make_check directory is missing or corrupted, you may need to restore it from a backup or re-extract the source code from the installation media.
If none of these solutions work, you may need to troubleshoot the problem further by examining the log files and error messages produced by the make buildworld command.
For more information about the make buildworld command and building the FreeBSD operating system from the source code, you can refer to the FreeBSD documentation and the make man page by running man make on the command line.