The file encoding is in fact utf-8, and it contains an 'é'. This probably relates the gdp or the checker. The former knows about the encoding. The latter tries to ensure the file is utf-8. Something wrongly claimed the encoding was ascii.
Exception in thread Thread-1:
Traceback (most recent call last):
File "/usr/lib/python2.7/threading.py", line 552, in __bootstrap_inner
self.run()
File "/home/curtis/.local/share/gedit/plugins/gdp/format.py", line 104, in run
checker.check()
File "/usr/lib/pymodules/python2.7/pocketlint/formatcheck.py", line 366, in check
checker.check()
File "/usr/lib/pymodules/python2.7/pocketlint/formatcheck.py", line 489, in check
ElementTree.parse(StringIO(text), parser)
File "/usr/lib/python2.7/xml/etree/ElementTree.py", line 1183, in parse
tree.parse(source, parser)
File "/usr/lib/python2.7/xml/etree/ElementTree.py", line 656, in parse
parser.feed(data)
File "/usr/lib/python2.7/xml/etree/ElementTree.py", line 1641, in feed
self._parser.Parse(data, 0)
UnicodeEncodeError: 'ascii' codec can't encode character u'\xe9' in position 1972: ordinal not in range(128)