From e52434aa18058d458162cf1f7f8f8dbfb22f38eb Mon Sep 17 00:00:00 2001
From: Ted Bauer <tedbauer@google.com>
Date: Fri, 8 Mar 2024 20:56:42 +0000
Subject: [PATCH] aflags: make flag storage error message more user-friendly

Bug: 328577149
Test: adb shell stop && sleep 10 && adb shell aflags list
Change-Id: Idb28c93f883b72031cf3e1ff4e8d396c4df708e2
---
 tools/aconfig/aflags/src/device_config_source.rs | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/tools/aconfig/aflags/src/device_config_source.rs b/tools/aconfig/aflags/src/device_config_source.rs
index 2589f3d8a6..f1a1f0dc2d 100644
--- a/tools/aconfig/aflags/src/device_config_source.rs
+++ b/tools/aconfig/aflags/src/device_config_source.rs
@@ -104,11 +104,16 @@ fn read_device_config_output(command: &[&str]) -> Result<String> {
     if !output.status.success() {
         let reason = match output.status.code() {
             Some(code) => {
-                format!("exit code {}, output was {}", code, str::from_utf8(&output.stdout)?)
+                let output = str::from_utf8(&output.stdout)?;
+                if !output.is_empty() {
+                    format!("exit code {code}, output was {output}")
+                } else {
+                    format!("exit code {code}")
+                }
             }
             None => "terminated by signal".to_string(),
         };
-        bail!("failed to execute device_config: {}", reason);
+        bail!("failed to access flag storage: {}", reason);
     }
     Ok(str::from_utf8(&output.stdout)?.to_string())
 }