Strictures turns on strict and makes all warnings fatal. if run within test cases from vcs checkouts, it will also cause bareword filehandles, indirect object syntax and multidimensional array emulation to raise a fatal error. to actually turn on these checks and stop strictures to complain about missing modules, the recommended packages libbareword-filehandles-perl, libindirect-perl and libmultidimensional-perl need to be installed.