po4a::man: This page defines a new macro 'Blob' with '.de' (inline comment: extra explanation), but you did not specify the expected po4a behavior when 'Blob' is used. You will get an error if this macro is actually used in your page.
Add your macro to one of the 'untranslated', 'noarg', 'translate_joined', 'translate_each', 'no_wrap' or 'inline' parameters to avoid issues.
For example, passing '-o untranslated=Blob' to po4a will ensure that the defined macro remains hidden from translators.
Please refer to the manpage of Locale::Po4a::Man for more info on these parameters.