Fix gps solver tests

Stupid variable assignment in loop was broken. Also, add one more test
case to check that a root require causes corresponding constraints to be
activated.

internal/gps/solve_bimodal_test.go

@@ -887,6 +887,23 @@ var bimodalFixtures = map[string]bimodalFixture{
 			"baz 1.0.0",
 		),
 	},
+	"require activates constraints": {
+		ds: []depspec{
+			dsp(mkDepspec("root 0.0.0", "foo 1.0.0", "bar 1.0.0"),
+				pkg("root", "foo")),
+			dsp(mkDepspec("foo 1.0.0"),
+				pkg("foo", "bar")),
+			dsp(mkDepspec("bar 1.0.0"),
+				pkg("bar")),
+			dsp(mkDepspec("bar 1.1.0"),
+				pkg("bar")),
+		},
+		require: []string{"bar"},
+		r: mksolution(
+			"foo 1.0.0",
+			"bar 1.0.0",
+		),
+	},
 	"require subpackage": {
 		ds: []depspec{
 			dsp(mkDepspec("root 0.0.0", "bar 1.0.0"),

internal/gps/solve_test.go

@@ -74,6 +74,7 @@ func TestBasicSolves(t *testing.T) {
 
 	sort.Strings(names)
 	for _, n := range names {
+		n := n
 		t.Run(n, func(t *testing.T) {
 			t.Parallel()
 			solveBasicsAndCheck(basicFixtures[n], t)
@@ -116,6 +117,7 @@ func TestBimodalSolves(t *testing.T) {
 
 	sort.Strings(names)
 	for _, n := range names {
+		n := n
 		t.Run(n, func(t *testing.T) {
 			t.Parallel()
 			solveBimodalAndCheck(bimodalFixtures[n], t)