The example code for errors.As (viewed at https://pkg.go.dev/errors?tab=doc#As) is the entire contents of the wrap_test.go file. It should be just func ExampleAs() { ... } I presume.

In talking this over with @FiloSottile, this may be a more systemic issue which can be improved in godoc. For example, we have the same issue with the chacha20poly1305.NewX example code. However, perhaps we should fix the example for the errors package for now either way.

While we're in there, perhaps we should check if there are any improvements to the documentation for errors as tracked in #31716.

/cc @jba @mpvl