/cc @robpike for further comments.

Please show a complete, compact program that illustrates the problem.

https://play.golang.org/p/idvKWcdTPiI

By commenting out line 36(BWithPointerData()) you can see that it works when a pointer is given and not vice versa.
I was a bit confused at the time of reporting this, I think a simple warning/comment in the documentation warning about this would have made my day a lot easier, and I expect this will help other people too.

This is how Go works. I'm not sure it's the gob's package job to explain the difference between the method sets of pointers and values.

https://golang.org/doc/faq#different_method_sets

I think it would be more convenient if there would be a reference to the faq in the gob(and JSON...) documentation.
If you encounter something you can't figure out, you look at the definition(of the interface in this case), not the general faq.
Although I thought it "worked" with JSON, it also doesn't encode with a pointer method, but it does decode using the unmarshal method(unlike gob).

If you encounter something you can't figure out, you look at the definition(of the interface in this case), not the general faq.

If that "something" is not related to that type, I think that expectation is incorrect. If I am working with encoding/json, and I cannot figure out how slice append work, I do not expect that to be explained in the interface definition.

Method sets are a design of the programming language itself and not specific to any package. I don't think adding a link to the FAQ just in gob and json, for something that is general to the programming language, is very helpful.

It is clearly documented in the spec and also in the FAQ.

I am going to close this as the original issue title is resolved. There is no issue with encoding/gob. If you feel method sets need to be documented more prominently, please feel free to open an issue with suggestions, and with reasoning explaining why the current documentation is not enough. Thanks.