[Autoroll] Display license script output in Skia->Flutter roller cloud logs

This is to make it easier to diagnose failures instead of having to run the license script manually.

Bug: skia:8658
Change-Id: I608aff57811a3d06e653b70b8136762b25ca9105
Reviewed-on: https://skia-review.googlesource.com/c/181224
Commit-Queue: Ravi Mistry <rmistry@google.com>
Reviewed-by: Eric Boren <borenet@google.com>
diff --git a/autoroll/go/repo_manager/pre_upload_steps.go b/autoroll/go/repo_manager/pre_upload_steps.go
index e917c91..5e27307 100644
--- a/autoroll/go/repo_manager/pre_upload_steps.go
+++ b/autoroll/go/repo_manager/pre_upload_steps.go
@@ -113,7 +113,12 @@
 	licensesGoldenDir := filepath.Join(parentRepoDir, "ci", "licenses_golden")
 	licenseCmd := []string{dartBinary, "lib/main.dart", "--src", "../../..", "--out", licensesOutDir, "--golden", licensesGoldenDir}
 	sklog.Infof("Running %s", licenseCmd)
-	if _, err := exec.RunCwd(ctx, licenseToolsDir, licenseCmd...); err != nil {
+	if err := exec.Run(ctx, &exec.Command{
+		Dir:            licenseToolsDir,
+		Name:           licenseCmd[0],
+		Args:           licenseCmd[1:],
+		CombinedOutput: os.Stdout,
+	}); err != nil {
 		return fmt.Errorf("Error when running dart license script: %s", err)
 	}
 
@@ -146,9 +151,10 @@
 		}
 		if err := exec.Run(ctx, &exec.Command{
 			Dir:    licenseToolsDir,
-			Name:   dartBinary,
-			Args:   []string{"lib/main.dart", "--release", "--src", "../../..", "--out", licensesOutDir},
+			Name:   updateLicenseCmd[0],
+			Args:   updateLicenseCmd[1:],
 			Stdout: outFile,
+			Stderr: os.Stderr,
 		}); err != nil {
 			return fmt.Errorf("Error when running dart license script: %s", err)
 		}
diff --git a/autoroll/go/repo_manager/pre_upload_steps_test.go b/autoroll/go/repo_manager/pre_upload_steps_test.go
index d866021..d2ce913 100644
--- a/autoroll/go/repo_manager/pre_upload_steps_test.go
+++ b/autoroll/go/repo_manager/pre_upload_steps_test.go
@@ -69,7 +69,7 @@
 	dartErr = errors.New("dart error")
 	err = FlutterLicenseScripts(ctx, nil, "testing/dir")
 	assert.Error(t, err)
-	assert.Equal(t, "Error when running dart license script: dart error; Stdout+Stderr:\n", err.Error())
+	assert.Equal(t, "Error when running dart license script: dart error", err.Error())
 
 	pubErr = error(nil)
 	dartErr = error(nil)