GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
LoadPackage( "congruence" );
TestDirectory(DirectoriesPackageLibrary( "congruence", "tst" ),
rec(exitGAP := true,
testOptions := rec(compareFunction := "uptowhitespace") ) );
FORCE_QUIT_GAP(1); # if we ever get here, there was an error