No, that should be fine (it just means that you won’t benefit from the caching). But you could add nengo.rc.set("decoder_cache", "enabled", False) if you want to explicitly disable the cache and avoid those warnings.
Found this thread while googling for documentation. You’ll want to use:
nengo.rc.set("decoder_cache", "enabled", "False")
("False" instead of False) otherwise you’ll get:
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-2-4005b404c25d> in <module>
1 import nengo
----> 2 nengo.rc.set("decoder_cache", "enabled", False)
~/anaconda3/envs/py36/lib/python3.6/configparser.py in set(self, section, option, value)
1190 """Set an option. Extends RawConfigParser.set by validating type and
1191 interpolation syntax on the value."""
-> 1192 self._validate_value_types(option=option, value=value)
1193 super().set(section, option, value)
1194
~/anaconda3/envs/py36/lib/python3.6/configparser.py in _validate_value_types(self, section, option, value)
1175 if not self._allow_no_value or value:
1176 if not isinstance(value, str):
-> 1177 raise TypeError("option values must be strings")
1178
1179 @property
TypeError: option values must be strings