The documentation for the module plugin, ns.col2.foo, was malformed.
The errors were:
7 validation errors for ModuleDocSchema
doc -> short_description
Field required (type=missing)
doc -> seealso
Input should be a valid list (type=list_type)
doc -> options -> bar -> description -> 0
Input should be a valid string (type=string_type)
doc -> options -> bar -> description -> 1
Input should be a valid string (type=string_type)
doc -> options -> bar -> type
Input should be 'any', 'bits', 'bool', 'bytes', 'dict', 'float', 'int', 'json', 'jsonarg', 'list', 'path', 'raw', 'sid', 'str', 'tmppath', 'pathspec' or 'pathlist' (type=literal_error; expected='any', 'bits', 'bool', 'bytes', 'dict', 'float', 'int', 'json', 'jsonarg', 'list', 'path', 'raw', 'sid', 'str', 'tmppath', 'pathspec' or 'pathlist')
doc -> options -> foo
Input should be a valid dictionary or instance of ModuleOptionsSchema (type=model_type; class_name=ModuleOptionsSchema)
doc -> options -> subfoo -> bam
Extra inputs are not permitted (type=extra_forbidden)
File a bug with the ns.col2 collection in order to have it corrected.