MySQL  8.0.21
Source Code Documentation
Test Framework System Requirements

The mysqltest and mysql_client_test programs are written in C++ and are available on any system where MySQL itself can be compiled, or for which a binary MySQL distribution is available.

Other parts of the test framework such as are Perl scripts and should run on systems with Perl installed.

mysqltest uses the diff program to compare expected and actual test results. If diff is not found, mysqltest writes an error message and dumps the entire contents of the .result and .reject files so that you can try to determine why a test did not succeed. If your system does not have diff, you may be able to obtain it from one of these sites: cannot function properly if started from within a directory whose full path includes a space character, due to the complexities of handling this correctly in all the different contexts it will be used.