Golang build tags/constraints (Neovim)

[Sam White]

I have an almost perfectly working YCM setup, the only issue I have at present is Go build constraints.

I'd imagine this is a feature request, or me missing some configuration rather than an issue with the installation, however FYI my YCM is complied from source and loaded via the VIM8 packages method.

The problem I'm seeing is that no files seem to be evaluated by YCM if they have a build constraint, I'll try to detail the set up below:

// main.go

package main

func main() {
  cf := config{}
  cf. // no field completions here
}

// config.go

// +build someTag

package main

type config struct {
  key string
}

This would suggest YCM has a knowledge of the constrained files and is omitting the completion because it hasn't been told to use those tags. Is there a way of supplying these tags to YCM? If so how is this done? It would be really beneficial to be able to supply default tags to use, as well as change them on the fly.

Thanks in advance - please let me know if you need any further info.

Sam

[Ben Jackson]

YCM uses gopls under the hood for Go semantic engine.

Googling for 'gopls build tags' yields some issues such as https://github.com/golang/go/issues/29202

I suspect this might be a limitation of gopls at the moment, but it at least looks like you can specify a set of build tags in the GOFLAGS environment variable.

"go.toolsEnvVars": {
    "GOFLAGS": "-tags=test"
},

You should be able to put that in your Settings function return. See here: https://github.com/ycm-core/YouCompleteMe#lsp-configuration and here: https://github.com/ycm-core/ycmd#lsp-based-completers

[Sam White]

Thanks for the tip, I can confirm setting those env vars does the trick.