When upgrading to ruby 3.1, I am seeing the following sort error message when using YAML.load_file some_file_name
Psych::DisallowedClass:
Tried to load unspecified class: Matrix
Other load statements causes similar errors but cite different unspecified clasees e.g. OpenStruct. It appears that the latest version of YAML only loads classes from a permitted white list, so it is necessary to use a permitted_class keyword to allow other classes. I have tried
hsh = YAML.load_file some_file_name, permitted_classes: [Matrix, OpenStruct]
but this gives the error
Psych::DisallowedClass:
Tried to load unspecified class: Symbol
how do I fix this.
Symbol is also not allowed per default. Therefore just add Symbol to the permitted_classes too:
hash = YAML.load_file(
some_file_name,
permitted_classes: [Matrix, OpenStruct, Symbol]
)
See the list of default permitted_classes.