Third-party libraries are not supported

[holenlv]

If third-party libraries is installed in $GOPATH/src ,It works well
But it doesn't work if installed in project/vendor

[roxma]

I cannot reproduce the issue.

If you could reproduce the issue with vim-go, set omnifunc=go#complete#Complete and <c-x><c-o>, it's more likely to be gocode issue.

[jsfaint]

Recently, maybe after Go 1.11 was released.
The behavior of Go completion became very weird.
Some code can be completed with lsp (go-langserve), but can't be completed with ncm2-go.

For example, here are two completion item, the first from ncm2-go, the second from lsp

Then input ., there are only lsp result left, no result from ncm2-go

[jsfaint]

I changed gocode from https://github.com/mdempsky/gocode to https://github.com/stamblerre/gocode.
The issue above was resolved.

Currently gocode has 3 forks on the table, but they all have some different issues.
The original: https://github.com/nsf/gocode
The active fork: https://github.com/mdempsky/gocode
Go module support: https://github.com/stamblerre/gocode

[jsfaint]

And I also find this issue
mdempsky/gocode#32

This is known issue. gocode make candidates from current package or standard package. So you must enable source importer with -source flag.

If you use vim-go, please try this.

diff --git a/autoload/go/complete.vim b/autoload/go/complete.vim
index 127d57f..279b10c 100644
--- a/autoload/go/complete.vim
+++ b/autoload/go/complete.vim
@@ -9,6 +9,7 @@ function! s:gocodeCommand(cmd, args) abort
   let cmd = [bin_path]
   let cmd = extend(cmd, ['-sock', socket_type])
   let cmd = extend(cmd, ['-f', 'vim'])
+  let cmd = extend(cmd, ['-source'])
   let cmd = extend(cmd, [a:cmd])
   let cmd = extend(cmd, a:args)
 

It looks we need to add parameter -source for gocode

[jsfaint]

I found another solution for this case.
Run go build -i, it will install the third-party library into $GOPATH/pkg, then everything will be OK.

[fcying]

@jsfaint
I add -source in args, it can complete github.com/sciter-sdk/go-sciter/window, But the completion is too slow.

        args = args = [gocode, '-f', 'json', '-source',                                                                                                    
                       'autocomplete', filepath, '%s' % offset]

and I test deoplete-go, It can complete and fast, I don't know how it is implemented

[jsfaint]

Yes, -source is very slow. You can use go build -i to build the library you use, then the completion will works well.

The -i flag installs the packages that are dependencies of the target.

[fcying]

@jsfaint after go build -i , it can autocomplete fast. just a little trouble. Every time you import a new package, you have to build it at first.

Or it can be use a cache? This will slow at first complete(with -source).

[jsfaint]

@fcying gocode usage below:

$ gocode -h
Usage: gocode [-s] [-f=<format>] [-in=<path>] [-sock=<type>] [-addr=<addr>]
       <command> [<args>]

Flags:
  -addr string
        address for tcp socket (default "127.0.0.1:37373")
  -builtin
        propose completions for built-in functions and types
  -debug
        enable server-side debug mode
  -f string
        output format (vim | emacs | nice | csv | json) (default "nice")
  -fallback-to-source
        if importing a package fails, fallback to the source importer
  -ignore-case
        do case-insensitive matching
  -in string
        use this file instead of stdin input
  -s    run a server instead of a client
  -sock string
        socket type (unix | tcp | none) (default "unix")
  -source
        use source importer
  -unimported-packages
        propose completions for standard library packages not explicitly importe                                                                               d

Commands:
  autocomplete [<path>] <offset>     main autocompletion command
  exit                               terminate the gocode daemon

gocode will import the binary package ($GOPATH/pkg/$GOOS_$GOARCH/) by default, if no parameter was given.

There are two parameter is related here: -source and -fallback-to-source

  -source
        use source importer

  -fallback-to-source
        if importing a package fails, fallback to the source importer

As you know, -source is very slow, and it doesn't support vendor package.
-fallback-to-source maybe a little fast in general case, but it doesn't support vendor pacakge too.
So the best workaround here is go build -i

I only use deoplete-go long time ago, it is very slow in that time.
I'm not sure what was changed since that

[fcying]

@jsfaint I test ncm2-vim-lsp + bingo, it work very well

Plug 'prabirshrestha/async.vim'
Plug 'prabirshrestha/vim-lsp'
Plug 'ncm2/ncm2-vim-lsp'
if executable('bingo')
    au User lsp_setup call lsp#register_server({
        \ 'name': 'bingo',
        \ 'cmd': {server_info->['bingo', '-mode', 'stdio']},
        \ 'whitelist': ['go'],
        \ })
endif

[jsfaint]

Yes, lsp is ok, but completion in ncm2-go and lsp server is different case.
All we talk about here is based on gocode

😄 you can also have a look on the Go official lsp server implementation.
https://github.com/golang/tools/tree/master/cmd/gopls

[ttys3]

I changed gocode from https://github.com/mdempsky/gocode to https://github.com/stamblerre/gocode. The issue above was resolved.

Currently gocode has 3 forks on the table, but they all have some different issues.
The original: https://github.com/nsf/gocode
The active fork: https://github.com/mdempsky/gocode
Go module support: https://github.com/stamblerre/gocode

and now, all those forks is under maintance.

https://github.com/mdempsky/gocode:

For a better autocompletion experience with Go, we suggest you use the Go language server, gopls.
If you are looking for a version of gocode that works with Go modules, please see stamblerre/gocode.

https://github.com/stamblerre/gocode:

IMPORTANT: This fork of gocode is currently in maintenance mode. For a better development experience with Go modules, we suggest you use the Go language server, gopls.