[MapProxy] Internal error with GetCapabilities WMS request

[Peter Sykora]

Hi,
I could successfully setup mapproxy with the default configuration on my 
server, except that I get an error accessing the capabilities document 
for WMS:
http://www.carto.net/mapproxy/service?REQUEST=GetCapabilities
I get the following errors:
2019-02-24 21:49:26,036 - CRITICAL - mapproxy.wsgiapp - fatal error in 
service for /service?REQUEST=GetCapabilities
Traceback (most recent call last):
   File 
"/home/sykora/mapproxy/mapproxy/lib/python3.6/site-packages/mapproxy/wsgiapp.py", 
line 193, in __call__
     resp = self.handlers[handler_name].handle(req)
   File 
"/home/sykora/mapproxy/mapproxy/lib/python3.6/site-packages/mapproxy/service/ows.py", 
line 38, in handle
     return self.services[service].handle(req)
   File 
"/home/sykora/mapproxy/mapproxy/lib/python3.6/site-packages/mapproxy/service/base.py", 
line 30, in handle
     return handler(parsed_req)
   File 
"/home/sykora/mapproxy/mapproxy/lib/python3.6/site-packages/mapproxy/service/wms.py", 
line 196, in capabilities
     ).render(map_request)
   File 
"/home/sykora/mapproxy/mapproxy/lib/python3.6/site-packages/mapproxy/service/wms.py", 
line 516, in render
     return self._render_template(_map_request.capabilities_template)
   File 
"/home/sykora/mapproxy/mapproxy/lib/python3.6/site-packages/mapproxy/service/wms.py", 
line 531, in _render_template
     inspire_md=inspire_md,
   File 
"/home/sykora/mapproxy/mapproxy/lib/python3.6/site-packages/mapproxy/util/ext/tempita/__init__.py", 
line 167, in substitute
     result, defs, inherit = self._interpret(ns)
   File 
"/home/sykora/mapproxy/mapproxy/lib/python3.6/site-packages/mapproxy/util/ext/tempita/__init__.py", 
line 178, in _interpret
     self._interpret_codes(self._parsed, ns, out=parts, defs=defs)
   File 
"/home/sykora/mapproxy/mapproxy/lib/python3.6/site-packages/mapproxy/util/ext/tempita/__init__.py", 
line 206, in _interpret_codes
     self._interpret_code(item, ns, out, defs)
   File 
"/home/sykora/mapproxy/mapproxy/lib/python3.6/site-packages/mapproxy/util/ext/tempita/__init__.py", 
line 226, in _interpret_code
     base = self._eval(parts[0], ns, pos)
   File 
"/home/sykora/mapproxy/mapproxy/lib/python3.6/site-packages/mapproxy/util/ext/tempita/__init__.py", 
line 301, in _eval
     reraise((exc_info[0], e, exc_info[2]))
   File 
"/home/sykora/mapproxy/mapproxy/lib/python3.6/site-packages/mapproxy/util/py.py", 
line 40, in reraise
     raise exc.with_traceback(tb)
   File 
"/home/sykora/mapproxy/mapproxy/lib/python3.6/site-packages/mapproxy/util/ext/tempita/__init__.py", 
line 288, in _eval
     value = eval(code, self.default_namespace, ns)
   File "<string>", line 1, in <module>
   File 
"/home/sykora/mapproxy/mapproxy/lib/python3.6/site-packages/mapproxy/util/ext/tempita/__init__.py", 
line 519, in __call__
     values = self._parse_signature(args, kw)
   File 
"/home/sykora/mapproxy/mapproxy/lib/python3.6/site-packages/mapproxy/util/ext/tempita/__init__.py", 
line 562, in _parse_signature
     % ', '.join(repr(v) for v in args))
TypeError: Extra position arguments: True at line 169 column 3 in file 
/home/sykora/mapproxy/mapproxy/lib/python3.6/site-packages/mapproxy/service/templates/wms111capabilities.xml

The GetMap requests work fine, eg.: 
http://www.carto.net/mapproxy/service?LAYERS=osm&FORMAT=image%2Fjpeg&SRS=EPSG%3A3857&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&BBOX=-5256910.9372448,-3015410.0118901,11277947.021405,8725317.5327129&WIDTH=845&HEIGHT=600
Thanks in advance for any hints
Peter