And they (somewhat/largely) avoid the “a test can’t check for issues we don’t know about” problem by running the GNU CoreUtils test suite, not a suite they wrot

And they (somewhat/largely) avoid the “a test can’t check for issues we don’t know about” problem by running the GNU CoreUtils test suite, not a suite they wrote themselves. (Browsing https://github.com/coreutils/coreutils/tree/master/tests https://github.com/coreutils/coreutils/tree/master/tests that test suite is written in shell and Perl)