:GoDoc flag doesn't work

[mattn]

Actual behavior

As far as I remember, :GoDoc flag works well. But says vim-go: gogetdoc: no documentation found

Expected behavior

No use gogetdoc.

Steps to reproduce:

Please create a reproducible case of your problem. Re produce it
with a minimal vimrc with all plugins disabled and only vim-go
enabled:

1. open some go file
2. :GoDoc flag

Configuration

On windows, But same on linux

• vim version: latest
• vim-go version: latest
• go version: latest