I am only going to speak to gopls as that is the only solution the go team is likely to add features to moving forwards.
gopls currently cannot work correctly on any package that has no persisted files, the issue is being tracked in #31307
It also will not auto-complete for things that are not imported into the current file. We have a lot of plans to improve auto complete in the future, but there are other higher priority features we need to add first (like rename and find references)

@ianthehat
I think the focus of gopls should be on completion. The rename and reference features are supported in coc and other completion plugins. At present, I think the biggest problem is that there is no easy to use complement in vim and other editors.

Edit: I upgraded from Go 1.12.3 to 1.12.4 and it fixed my issue. Sorry for the noise.

Running into the first issue mentioned. Seems specific to net(/*) as an import—completion for everything breaks when imported.

Using gopls with vim-go but I'm thinking this isn't vim-go related since I can reproduce by making queries directly.

package main

import "fmt"
import "net"

func main() {
        fmt.Println("vim-go")
}

$GOPATH/bin/gopls query definition /home/eddiezane/Desktop/herp/main.go:#67
definition: /home/eddiezane/Desktop/herp/main.go:#67: no file information for file:///home/eddiezane/Desktop/herp/main.go

{"method":"textDocument/didChange","jsonrpc":"2.0","params":{"contentChanges":[{"text":"package main\n\nimport \"fmt\"\nimport \"net/http\"\n\nfunc main() {\n\tfmt.Pr
intln(\"vim-go\")\n\thttp.\n}\n"}],"textDocument":{"uri":"file:///home/eddiezane/Desktop/herp/main.go"}}}', '->
Content-Length: 175

{"method":"textDocument/completion","jsonrpc":"2.0","id":2,"params":{"textDocument":{"uri":"file:///home/eddiezane/Desktop/herp/main.go"},"position":{"character":6,"l
ine":7}}}', '<-
Content-Length: 135

{"jsonrpc":"2.0","error":{"code":0,"message":"no file information for file:///home/eddiezane/Desktop/herp/main.go","data":null},"id":2}']

Change https://golang.org/cl/172409 mentions this issue: go/packages: add support for entire packages defined in overlays

@stamblerre - following https://go-review.googlesource.com/c/tools/+/172409/ I'm still seeing an issue in the test in #31338 (was closed in favour of this issue), i.e. completions are not working for unpersisted imports. Should I open another issue for that or ...?

I tested it and didn't see it fixed. My friend and I are making a new lsp instead of gopls, hope that gopls will become mature enough.

The issue with this bug is it's difficult to reverse engineer the package path given the filename and the package declaration. #31522 is tracking further improvements to the overlays in go/packages, but right now we don't handle main packages or x_tests.

@myitcv: I expect that if you try the same case with a non-main file it should work. Filed #31542.

Closing this issue in favor of #31542.

@stamblerre #31542 is closed. but i dont find the problem solved. gopls also doesnt work on unsaved buffer when i import a new thirty package.

It's possible that there has been a recent regression. I will reopen this issue and investigate. Thanks for pointing this out.

It seems like this is actually an issue with go/packages, so I filed a new bug: #33482. Closing this issue in favor of the new one.

@stamblerre hi, i found the #33482 is closed.but i found this issue still exist. I believe that many developers import many third-party packages in their daily work, but gopls can't work in this kind of scenario. I have discussed this problem with my colleagues, we are bothered by this, every time I import a thirty package ,I need to save and restart vim or emacs . I would like to know the go team's view on this issue. This problem has been around for a long time. At least I created this issue last year.
this gif worked in master gopls by go get golang.org/x/tools/gopls@master

@taigacute: I am not able to reproduce this issue myself. We have added a lot of overlay support to go/packages, so almost everything should work out of the box. Which client are you using for Vim or Emacs? Is the third-party package that you are importing in your module cache?

@stamblerre gif is vim，also i use emacs。reproduce step。

1. mkdir test
2. go mod init test
3. touch main.go
4. import a thirty package

what i missed ?

Sorry, by client I meant - which plugin are you using for the LSP? Is this with vim-go, ale, etc. (see https://github.com/golang/tools/blob/master/gopls/doc/vim.md for a full list)? Is this package something that you've imported before, i.e. is it available in your module cache ($GOPATH/pkg/mod)?

@stamblerre i used coc.nvim .yeah the package in my $GOPATH/pkg/mod