name 'unicode' is not defined

[irene]

I am using the recent version of mediagoblin.
But I have a fatal error raising the mediagoblin server. Here the error output:

$ ./lazyserver.sh --server-name=fcgi fcgi_host=127.0.0.1 fcgi_port=26543
Using paster config: paste_local.ini
Using ./bin/paster
+ export CELERY_ALWAYS_EAGER=true
+ CELERY_ALWAYS_EAGER=true
+ case "$selfname" in
+ ./bin/paster serve paste_local.ini --server-name=fcgi fcgi_host=127.0.0.1 
fcgi_port=26543 --reload
Starting subprocess with file monitor
2020-02-06 11:45:47,024 INFO    [mediagoblin.app] GNU MediaGoblin 1.0.dev main 
server starting
2020-02-06 11:45:47,136 INFO    [mediagoblin.app] Setting up plugins.
2020-02-06 11:45:47,136 INFO    [mediagoblin.init.plugins] Importing plugin 
module: mediagoblin.plugins.geolocation
2020-02-06 11:45:47,137 INFO    [mediagoblin.init.plugins] Importing plugin 
module: mediagoblin.plugins.basic_auth
2020-02-06 11:45:47,137 INFO    [mediagoblin.init.plugins] Importing plugin 
module: mediagoblin.plugins.processing_info
2020-02-06 11:45:47,137 INFO    [mediagoblin.init.plugins] Importing plugin 
module: mediagoblin.media_types.image
2020-02-06 11:45:47,294 INFO    [mediagoblin.init.celery] Setting celery 
configuration from object "mediagoblin.init.celery.dummy_settings_module"
Starting server in PID 4301.
Traceback (most recent call last):
  File "./bin/paster", line 11, in <module>
    load_entry_point('PasteScript', 'console_scripts', 'paster')()
  File 
"/srv/http/mediagoblin.localhost.local/mediagoblin/lib/python3.6/site-packages/PasteScript-3.2.0-py3.6.egg/paste/script/command.py",
 line 102, in run
    invoke(command, command_name, options, args[1:])
  File 
"/srv/http/mediagoblin.localhost.local/mediagoblin/lib/python3.6/site-packages/PasteScript-3.2.0-py3.6.egg/paste/script/command.py",
 line 141, in invoke
    exit_code = runner.run(args)
  File 
"/srv/http/mediagoblin.localhost.local/mediagoblin/lib/python3.6/site-packages/PasteScript-3.2.0-py3.6.egg/paste/script/command.py",
 line 236, in run
    result = self.command()
  File 
"/srv/http/mediagoblin.localhost.local/mediagoblin/lib/python3.6/site-packages/PasteScript-3.2.0-py3.6.egg/paste/script/serve.py",
 line 319, in command
    serve()
  File 
"/srv/http/mediagoblin.localhost.local/mediagoblin/lib/python3.6/site-packages/PasteScript-3.2.0-py3.6.egg/paste/script/serve.py",
 line 303, in serve
    server(app)
  File 
"/srv/http/mediagoblin.localhost.local/mediagoblin/lib/python3.6/site-packages/PasteDeploy-2.1.0-py3.6.egg/paste/deploy/loadwsgi.py",
 line 195, in server_wrapper
    **context.local_conf)
  File 
"/srv/http/mediagoblin.localhost.local/mediagoblin/lib/python3.6/site-packages/PasteDeploy-2.1.0-py3.6.egg/paste/deploy/util.py",
 line 55, in fix_call
    val = callable(*args, **kw)
  File 
"/srv/http/mediagoblin.localhost.local/mediagoblin/lib/python3.6/site-packages/flup-1.0.3-py3.6.egg/flup/server/paste_factory.py",
 line 138, in run_fcgi_fork
    debug = asbool(debug)
  File 
"/srv/http/mediagoblin.localhost.local/mediagoblin/lib/python3.6/site-packages/flup-1.0.3-py3.6.egg/flup/server/paste_factory.py",
 line 7, in asbool
    if isinstance(obj, (str, unicode)):
NameError: name 'unicode' is not defined