It seems your test uses require with a string value, e.g.

require 'MAS::Global';
# or
my $class = 'MAS::Global';
require $class;
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That's not how require works. In fact, the documentation of the command tells you exactly that:

If EXPR is a bareword, "require" assumes a .pm extension and replaces "::" with "/" in the filename for you, to make it easy to load standard modules. This form of loading of modules does not risk altering your namespace.
In other words, if you try this:

                    require Foo::Bar;     # a splendid bareword
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The require function will actually look for the Foo/Bar.pm file in the directories specified in the @INC array.
But if you try this:

                    my $class = 'Foo::Bar';
                    require $class;       # $class is not a bareword
                #or
                    require "Foo::Bar";   # not a bareword because of 
+the ""
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The require function will look for the Foo::Bar file in the @INC array and will complain about not finding Foo::Bar there. In this case you can do:

                    eval "require $class";
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