make test work with and without bzlmod

go/tools/gopackagesdriver/gopackagesdriver_test.go

@@ -191,19 +191,25 @@ func TestIncompatible(t *testing.T) {
  t.Fatalf("unmarshaling response: %v", err)
  }
 
- helloLabel := "@@//:hello"
- incompatibleLabel := "@@//:incompatible"
- var foundHello bool
+ rootLabels := make(map[string]bool)
  for _, root := range resp.Roots {
- if root == helloLabel {
- foundHello = true
- }
- if root == incompatibleLabel {
- t.Errorf("response contains root %s", incompatibleLabel)
- }
+ rootLabels[root] = true
  }
- if !foundHello {
- t.Errorf("response does not contain root %s; roots were %s", helloLabel, strings.Join(resp.Roots, ", "))
+
+ // Verify //:hello is in .Roots and check whether its label starts with
+ // "@@" (bzlmod) or "@" (not bzlmod).
+ var incompatibleLabel string
+ if rootLabels["@@//:hello"] {
+ incompatibleLabel = "@@//:incompatible"
+ } else if rootLabels["@//:hello"] {
+ incompatibleLabel = "@//:incompatible"
+ } else {
+ t.Fatalf("response does not contain //:hello; roots were %s", strings.Join(resp.Roots, ", "))
+ }
+
+ // Verify //:incompatible is NOT in .Roots.
+ if rootLabels[incompatibleLabel] {
+ t.Fatalf("response contains root %s", incompatibleLabel)
  }
 }