all: add -mod=vendor to GOFLAGS in tests that execute 'go' commands within std or cmd

Updates #30228
Updates #30240
Updates #30241

Change-Id: Idc311ba77e99909318b5b86f8ef82d4878f73e47
Reviewed-on: https://go-review.googlesource.com/c/go/+/165378
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

11 files changed, 22 insertions, 1 deletions

diff --git a/src/cmd/addr2line/addr2line_test.go b/src/cmd/addr2line/addr2line_test.go
index 22bf1379bb..183a22f8f3 100644
--- a/src/cmd/addr2line/addr2line_test.go
+++ b/src/cmd/addr2line/addr2line_test.go
@@ -115,3 +115,5 @@ func TestAddr2Line(t *testing.T) {
 	testAddr2Line(t, exepath, syms[symName])
 	testAddr2Line(t, exepath, "0x"+syms[symName])
 }
+
+func init() { testenv.SetModVendor() }
diff --git a/src/cmd/compile/internal/gc/scope_test.go b/src/cmd/compile/internal/gc/scope_test.go
index e327dc02af..e4861c686c 100644
--- a/src/cmd/compile/internal/gc/scope_test.go
+++ b/src/cmd/compile/internal/gc/scope_test.go
@@ -202,6 +202,8 @@ var testfile = []testline{
 
 const detailOutput = false
 
+func init() { testenv.SetModVendor() }
+
 // Compiles testfile checks that the description of lexical blocks emitted
 // by the linker in debug_info, for each function in the main package,
 // corresponds to what we expect it to be.
diff --git a/src/cmd/cover/cover_test.go b/src/cmd/cover/cover_test.go
index f002442b63..d7e6ca99b7 100644
--- a/src/cmd/cover/cover_test.go
+++ b/src/cmd/cover/cover_test.go
@@ -77,6 +77,8 @@ var debug = flag.Bool("debug", false, "keep rewritten files for debugging")
 // We use TestMain to set up a temporary directory and remove it when
 // the tests are done.
 func TestMain(m *testing.M) {
+	testenv.SetModVendor()
+
 	dir, err := ioutil.TempDir("", "gotestcover")
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err)
diff --git a/src/cmd/go/go_test.go b/src/cmd/go/go_test.go
index dfada6c806..9ba52e609e 100644
--- a/src/cmd/go/go_test.go
+++ b/src/cmd/go/go_test.go
@@ -212,7 +212,9 @@ func TestMain(m *testing.M) {
 			return
 		}
 
-		out, err := exec.Command(gotool, args...).CombinedOutput()
+		buildCmd := exec.Command(gotool, args...)
+		buildCmd.Env = append(os.Environ(), "GOFLAGS=-mod=vendor")
+		out, err := buildCmd.CombinedOutput()
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "building testgo failed: %v\n%s", err, out)
 			os.Exit(2)
diff --git a/src/cmd/internal/obj/x86/obj6_test.go b/src/cmd/internal/obj/x86/obj6_test.go
index c5399744f2..2b1a729c8f 100644
--- a/src/cmd/internal/obj/x86/obj6_test.go
+++ b/src/cmd/internal/obj/x86/obj6_test.go
@@ -134,6 +134,8 @@ func parseOutput(t *testing.T, td *ParsedTestData, asmout []byte) {
 	}
 }
 
+func init() { testenv.SetModVendor() }
+
 func TestDynlink(t *testing.T) {
 	testenv.MustHaveGoBuild(t)
 
diff --git a/src/cmd/link/internal/ld/ld_test.go b/src/cmd/link/internal/ld/ld_test.go
index 0816429316..219b2a63ca 100644
--- a/src/cmd/link/internal/ld/ld_test.go
+++ b/src/cmd/link/internal/ld/ld_test.go
@@ -13,6 +13,8 @@ import (
 	"testing"
 )
 
+func init() { testenv.SetModVendor() }
+
 func TestUndefinedRelocErrors(t *testing.T) {
 	t.Parallel()
 	testenv.MustHaveGoBuild(t)
diff --git a/src/cmd/link/link_test.go b/src/cmd/link/link_test.go
index 5200c3a6f0..5043a778ca 100644
--- a/src/cmd/link/link_test.go
+++ b/src/cmd/link/link_test.go
@@ -38,6 +38,8 @@ func TestLargeSymName(t *testing.T) {
 	_ = AuthorPaidByTheColumnInch
 }
 
+func init() { testenv.SetModVendor() }
+
 func TestIssue21703(t *testing.T) {
 	t.Parallel()
 
diff --git a/src/cmd/nm/nm_test.go b/src/cmd/nm/nm_test.go
index 8176ddd7f4..82f4235510 100644
--- a/src/cmd/nm/nm_test.go
+++ b/src/cmd/nm/nm_test.go
@@ -30,6 +30,8 @@ func testMain(m *testing.M) int {
 		return 0
 	}
 
+	testenv.SetModVendor()
+
 	tmpDir, err := ioutil.TempDir("", "TestNM")
 	if err != nil {
 		fmt.Println("TempDir failed:", err)
diff --git a/src/cmd/objdump/objdump_test.go b/src/cmd/objdump/objdump_test.go
index a2ca329609..7c874e853b 100644
--- a/src/cmd/objdump/objdump_test.go
+++ b/src/cmd/objdump/objdump_test.go
@@ -24,6 +24,8 @@ func TestMain(m *testing.M) {
 	if !testenv.HasGoBuild() {
 		return
 	}
+	testenv.SetModVendor()
+
 	var exitcode int
 	if err := buildObjdump(); err == nil {
 		exitcode = m.Run()
diff --git a/src/cmd/vet/all/main.go b/src/cmd/vet/all/main.go
index 2500c690bf..8cc4140e6e 100644
--- a/src/cmd/vet/all/main.go
+++ b/src/cmd/vet/all/main.go
@@ -44,6 +44,7 @@ func main() {
 	log.SetPrefix("vet/all: ")
 	log.SetFlags(0)
 
+	testenv.SetModVendor()
 	var err error
 	cmdGoPath, err = testenv.GoTool()
 	if err != nil {
diff --git a/src/cmd/vet/vet_test.go b/src/cmd/vet/vet_test.go
index 5d8139d977..62c28fb9a2 100644
--- a/src/cmd/vet/vet_test.go
+++ b/src/cmd/vet/vet_test.go
@@ -32,6 +32,8 @@ func TestMain(m *testing.M) {
 }
 
 func testMain(m *testing.M) int {
+	testenv.SetModVendor()
+
 	dir, err := ioutil.TempDir("", "vet_test")
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err)