Scopelint check issue

General Questions
1

scopelint checks for unpinned variables in go programs.

Sample problem code like this:

values := []string{"a", "b", "c"}
var funcs []func()
for _, val := range values {
	 funcs = append(funcs, func() {
	 	 fmt.Println(val)
	 })
}

scoplint checks find:

Using the variable on range scope "val" in function literal
Using a reference for the variable on range scope "val"
Found 2 lint problems; failing.

The reason is, in Go, the val variable in the above loop is actually a single variable.

To fix it, there are three ways.
First, you can exclude functional literal check by adding the follow code in .golangci.yml

issues:
   exclude:
       - Using the variable on range scope .* in functional literal

Second, you can redefine this variable in loop.

values := []string{"a", "b", "c"}
var funcs []func()
for _, val := range values {
  val := val
	funcs = append(funcs, func() {
		fmt.Println(val)
	})
}

Third, you can ignore issues for the line, or the block of code, or the file.

var copies []*string
for _, val := range values {
	copies = append(copies, &val) //scopelint:ignore
}

var copies []*string
//scopelint:ignore
for _, val := range values {
	copies = append(copies, &val)
}

//scopelint:ignore
package pkg
2

Interesting topic. Looks like ignoring the lint may cause unexpected issues. I found a post detailed the issue here:

The more background of the issue of the single variable can be found in the link. And copying to a new variable seems to be a standard fix to avoid the issue.