cmd/go: mod vendor should ignore non-Go content

[reitzig]

Tl;dr: Go is not the only tool I use in my project; I expect it share vendor peacefully.

What version of Go are you using (go version)?

$ go version
go version go1.15.8 linux/amd64

(latest at the time of this writing)

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/raphael/.cache/go-build"
GOENV="/home/raphael/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/home/raphael/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/raphael/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/raphael/Code/tools/container-do/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build500284300=/tmp/go-build -gno-record-gcc-switches"

What did you do?

# Gemfile
source "https://rubygems.org"

group :test do
  gem 'cucumber', '~> 5'
  gem 'rspec', '~> 3'
end

# go.mod
module github.com/reitzig/container-do

go 1.15

require (
	github.com/pelletier/go-toml v1.8.1
	go.uber.org/zap v1.16.0
)

bundle2.7 config set --local path 'vendor/bundle'
bundle2.7 install
go mod vendor

What did you expect to see?

Ruby gems and Go modules "installed" in vendor.

What did you see instead?

Only Go modules in vendor.

Workaround

Bundler leaves Go modules alone, so re-running bundle install after go mod vendor creates the desired state.

[mvdan]

This seems like a duplicate of #26366.

[reitzig]

Very old and unsolved, but yes, essentially the same issue. Don't know if, after all this time, it refers to the same implementation anymore.

[bcmills]

Is there a typo in the issue title? I'm having trouble figuring out what the desired behavior is here.

[reitzig]

Is there a typo in the issue title?

I don't think so. What's your understanding of the expected behaviour?