syscall: append to environment in tests, don't clobber it

Fixes https://gcc.gnu.org/PR95061

Change-Id: I3cddfe5920b6da572ddeafa201617003c25175e6
Reviewed-on: https://go-review.googlesource.com/c/go/+/233318
Run-TryBot: Ian Lance Taylor <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-by: Brad Fitzpatrick <[email protected]>

Author: ianlancetaylor

src/syscall/exec_linux_test.go

@@ -355,7 +355,7 @@ func TestUnshareMountNameSpace(t *testing.T) {
 	}
 
 	cmd := exec.Command(os.Args[0], "-test.run=TestUnshareMountNameSpaceHelper", d)
-	cmd.Env = []string{"GO_WANT_HELPER_PROCESS=1"}
+	cmd.Env = append(os.Environ(), "GO_WANT_HELPER_PROCESS=1")
 	cmd.SysProcAttr = &syscall.SysProcAttr{Unshareflags: syscall.CLONE_NEWNS}
 
 	o, err := cmd.CombinedOutput()
@@ -406,7 +406,7 @@ func TestUnshareMountNameSpaceChroot(t *testing.T) {
 	}
 
 	cmd = exec.Command("/syscall.test", "-test.run=TestUnshareMountNameSpaceHelper", "/")
-	cmd.Env = []string{"GO_WANT_HELPER_PROCESS=1"}
+	cmd.Env = append(os.Environ(), "GO_WANT_HELPER_PROCESS=1")
 	cmd.SysProcAttr = &syscall.SysProcAttr{Chroot: d, Unshareflags: syscall.CLONE_NEWNS}
 
 	o, err := cmd.CombinedOutput()
@@ -621,7 +621,7 @@ func testAmbientCaps(t *testing.T, userns bool) {
 	}
 
 	cmd := exec.Command(f.Name(), "-test.run=TestAmbientCapsHelper")
-	cmd.Env = []string{"GO_WANT_HELPER_PROCESS=1"}
+	cmd.Env = append(os.Environ(), "GO_WANT_HELPER_PROCESS=1")
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
 	cmd.SysProcAttr = &syscall.SysProcAttr{

src/syscall/syscall_linux_test.go

@@ -187,7 +187,7 @@ func TestLinuxDeathSignal(t *testing.T) {
 	}
 
 	cmd := exec.Command(tmpBinary)
-	cmd.Env = []string{"GO_DEATHSIG_PARENT=1"}
+	cmd.Env = append(os.Environ(), "GO_DEATHSIG_PARENT=1")
 	chldStdin, err := cmd.StdinPipe()
 	if err != nil {
 		t.Fatalf("failed to create new stdin pipe: %v", err)
@@ -225,7 +225,10 @@ func TestLinuxDeathSignal(t *testing.T) {
 
 func deathSignalParent() {
 	cmd := exec.Command(os.Args[0])
-	cmd.Env = []string{"GO_DEATHSIG_CHILD=1"}
+	cmd.Env = append(os.Environ(),
+		"GO_DEATHSIG_PARENT=",
+		"GO_DEATHSIG_CHILD=1",
+	)
 	cmd.Stdin = os.Stdin
 	cmd.Stdout = os.Stdout
 	attrs := syscall.SysProcAttr{
@@ -356,7 +359,7 @@ func TestSyscallNoError(t *testing.T) {
 	}
 
 	cmd := exec.Command(tmpBinary)
-	cmd.Env = []string{"GO_SYSCALL_NOERROR=1"}
+	cmd.Env = append(os.Environ(), "GO_SYSCALL_NOERROR=1")
 
 	out, err := cmd.CombinedOutput()
 	if err != nil {