Gocode panicked: `[deoplete] NoneType: None`

[karlek]

This minimal config panicks everytime a key is pressed when writing in a go file.

call plug#begin('~/.vim/plugged')
Plug 'Shougo/deoplete.nvim', { 'do': ':UpdateRemotePlugins' }
Plug 'zchee/deoplete-go',    { 'do': 'make'}
call plug#end()
let g:deoplete#enable_at_startup = 1
let g:deoplete#sources#go#gocode_binary = '$GOPATH/bin/gocode'

There is very little information from the panic:

[deoplete] NoneType: None
gocode panicked.  Use :messages / see above for error details.

$ go version
go version go1.11 linux/amd64

[~/go/src/github.com/nsf/gocode] $ git rev-parse HEAD
7b1d4e18cdc58a74dc1bd4c2d45b3f1b2ca227c3

[Shougo]

You should use https://github.com/mdempsky/gocode instead. nsf/gocode does not support go 1.10+. Please read README in nsf/gocode. https://github.com/nsf/gocode

[karlek]

Thank you, that was the problem.

If someone else has this problem, don't forget to kill your old gocode daemon with gocode exit (or pkill gocode if necessary)

[cippaciong]

If anyone using go modules stumbles into this issue and is already using mdempsky/gocode, please notice that mdempsky version does not support modules. As suggested in the README, try using stamblerre/gocode. Remember to stop the daemon with gocode close, delete $GOPATH/bin/gocode and replace it with the newer version from stamblerre go get -u github.com/stamblerre/gocode