go lint tools range closure detection

Yes, correct. This problem is very common among Gophers (What happens with closures running as goroutines?)!

Go vet's issues:

1. https://github.com/golang/go/issues/21412
2. https://github.com/golang/go/issues/16520

So, it seems you don't see an output with go vet because the goroutine in within an if block. Could you try doing it without the if block? I think your issue is more relevant Issue 21412

Similarly for golangci/govet:

Quoting from the golangci/govet/rangeloop.go's code:

This file contains the code to check range loop variables bound inside function
literals that are deferred or launched in new goroutines. We only check
instances where the defer or go statement is the last statement in the loop
body, as otherwise, we would need whole-program analysis.

Also, my suggestion would be to check if tunnels are open and then only close it. It might happen that you duplicate entries, so then again there's a possibility of some issue. And do fix the closure running as a goroutine error, first.

So, here's an example where the if block is a differentiator on how go vet works.

• With if block, go vet returns nothing

package main

import (
        "fmt"
        "sync"
)

func main() {
        fruits := []string{"orange", "apple"}
        var wg sync.WaitGroup
        for _, fruit := range fruits {
                if true {
                        wg.Add(1)
                        go func() {
                                fmt.Println(fruit)
                                wg.Done()
                        }()
                }
        }
        wg.Wait()
}

• Without if block, go vet returns loop variable fruit captured by func literal

package main

import (
        "fmt"
        "sync"
)

func main() {
        fruits := []string{"orange", "apple"}
        var wg sync.WaitGroup
        for _, fruit := range fruits {
                wg.Add(1)
                go func() {
                        fmt.Println(fruit)
                        wg.Done()
                }()
        }
        wg.Wait()
}