Comment 1:

In file a.go you declared the variable a.X; in file b.go you declared the variable
main.X; the variables are distinct.

Comment 2:

That's not how I interpret the spec, but if that's the correct interpretation, the
spec also requires that the unused import be diagnosed.

Comment 3:

As you can see from this expanded version of file b.go, as expected, the most local
variable X (main.X) hides the imported variable X (a.X).
package main
import . "./a"
import a "./a"
import "fmt"
var X = 1
func main() {
    fmt.Println("X (main.X) = ", X, ", ", "a.X =", a.X)
}
which gives: X (main.X) =  1 ,  a.X = 0
The explicit period form of the package name imports all the package's exported
identifiers, whether they are used or not. Therefore, there is no error for the
unused imported identifiers.

Comment 4:

There should not be any "hiding".  The spec says variable X from b.go is declared in
the package scope.  The spec implies that variable X from import . "./a" should be
declared in file scope (the spec does not say this explicitly, but it does say that
imported package identifiers are declared at file scope).  Finally, the spec says "no
identifier may be declared in both the file and package block".
I understand that the reference implementation does not behave as I describe.  A
plausible resolution to this bug would be to change the spec.

Comment 5:

This is a real bug: the X should be a conflict,
and then if you delete the declaration of X
you should get an imported and not used error.

Owner changed to r...@golang.org.

Status changed to Accepted.

Comment 6:

Labels changed: added compilerbug.

Comment 7:

This issue was closed by revision 5a5799f.

Status changed to Fixed.

Merged into issue #-.