the SFNTReader expects the input file to be seekable, and it already rewinds the file with file.seek(0) to get to the sfnt table directory. Thus, if TTFont is loaded with an unseekable file object and lazy=True, we raise a TTLibError requiring one to either pass a seekable input file, or to not set lazy=True (in which case the input is loaded in a seekable BytesIO) Fixes https://github.com/fonttools/fonttools/issues/3052