Restore optional shell handling in launcher tests

scripts/release_test.go

@@ -60,12 +60,16 @@ esac
 
 func (f fixture) run(t *testing.T, script string, status int, args ...string) (string, string, int) {
 	t.Helper()
-	cmd := exec.Command(filepath.Join(f.root, "scripts", script), args...)
+	shell, err := exec.LookPath("sh")
+	if err != nil {
+		t.Skip("POSIX shell is unavailable")
+	}
+	cmd := exec.Command(shell, append([]string{filepath.Join(f.root, "scripts", script)}, args...)...)
 	cmd.Dir = f.outside
 	cmd.Env = append(os.Environ(), "PATH="+filepath.Dir(f.root)+string(os.PathListSeparator)+os.Getenv("PATH"), "CALLS="+f.log, fmt.Sprintf("TOOL_STATUS=%d", status), "CDPATH=/tmp", "GOOS=windows", "GOARCH=arm64", "GOWORK=auto", "GOTOOLCHAIN=auto", "GOFLAGS=-trimpath -mod=mod")
 	var stdout, stderr strings.Builder
 	cmd.Stdout, cmd.Stderr = &stdout, &stderr
-	err := cmd.Run()
+	err = cmd.Run()
 	if err == nil {
 		return stdout.String(), stderr.String(), 0
 	}
@@ -183,6 +187,17 @@ func TestStatusAndStreams(t *testing.T) {
 	}
 }
 
+func TestLauncherUsesShell(t *testing.T) {
+	f := newFixture(t)
+	if err := os.Chmod(filepath.Join(f.root, "scripts", "releasekit"), 0644); err != nil {
+		t.Fatal(err)
+	}
+	_, _, status := f.run(t, "releasekit", 0, "version")
+	if status != 0 {
+		t.Fatal(status)
+	}
+}
+
 func TestInvalidForms(t *testing.T) {
 	for _, tc := range []struct {
 		script string