I am the author of the Win32::SerialPort module. As one would expect from the name, it only runs properly on Win32. So the last update generated several "false" failures. The next update will add a $^O test and fix the prerequisites to address those.
So far, I have not had any complaints from users. So my question, especially relevant since there will be a lot of 5.12 testing, is whether is it considered proper to do a release just to address issues created for the CPAN testers? (The prior release predated the CPAN testers so the question never came up). -bill