dotnet/maui · error · Exception

Failed to push ADB keys after multiple attempts.

Error message

Failed to push ADB keys after multiple attempts.

What it means

Thrown when the ADB key-push retry loop exhausts all attempts without pushSuccess becoming true. Each attempt tries to adb push the generated adbkey.pub to the device's /data/misc/adb/adb_keys, retrying with a 1-second sleep between attempts.

Source

Thrown at eng/devices/android.cake:988

            
            var exitCode = StartProcess("adb", processSettings);
            
            // Check exit code for success indicators
            if (exitCode == 0)
            {
                Information("ADB key successfully pushed.");
                pushSuccess = true;
                break;
            }

            retries++;
            Information($"Push attempt {retries} failed. Retrying in 1 second...");
            System.Threading.Thread.Sleep(1000);
        }

        if (!pushSuccess)
        {
            throw new Exception("Failed to push ADB keys after multiple attempts.");
        }

        // Set proper permissions on the device key file
        AdbShell("chmod 600 /data/misc/adb/adb_keys", settings);

        // Restart ADB on device to apply changes
        Information("Restarting ADB daemon on the device...");
        AdbShell("stop adbd", settings);
        System.Threading.Thread.Sleep(2000);
        AdbShell("start adbd", settings);
        System.Threading.Thread.Sleep(2000);

        // Verify connectivity after all changes
        var deviceCheck = StartProcess("adb", new ProcessSettings {
            Arguments = "devices",
            RedirectStandardOutput = true
        });
        

View on GitHub (pinned to f377ff1c5e)

Solutions

1. Confirm the emulator/device is online: `adb devices` should list it without 'unauthorized'.
2. Restart adbd on the device (the script does this after a successful push; do it manually if needed) and re-run.
3. If 'unauthorized', accept the RSA fingerprint dialog on the device/emulator UI, or ensure the key being pushed matches the one adb is using.
4. Increase the retry count or add a longer backoff for flaky USB/emulator connections.

// Confirm device reachable + authorized before pushing
var state = SafeAdbShell("getprop sys.boot_completed", settings).FirstOrDefault();
if (state != "1") throw new Exception("Device not booted; cannot push ADB keys.");

int maxPushRetries = 5;
bool pushSuccess = false;
for (int i = 0; i < maxPushRetries && !pushSuccess; i++) {
    try {
        AdbPush(adbKeyPubFile, "/data/misc/adb/adb_keys", settings);
        pushSuccess = true;
    } catch (Exception ex) when (i < maxPushRetries - 1) {
        Warning($"Push attempt {i+1} failed: {ex.Message}");
        System.Threading.Thread.Sleep(1000 * (i + 1));
    }
}

When it happens

Trigger: Every `adb push` attempt in the loop fails (returns non-zero or throws) and pushSuccess never flips to true before retries is exhausted.

Common situations: The emulator is not actually running or not reachable via ADB; ADB authorization is pending and the device rejects the push; the destination path /data/misc/adb is not writable (e.g. on a production build); adbd is in a bad state.

Related errors

• All key generation methods failed. Unable to create ADB keys
• ADB keys were not created successfully.
• The emulator did not finish booting in time.
• Environment variable 'ANDROID_SDK_ROOT' or 'ANDROID_HOME' mu
• JAVA_HOME environment variable isn't set. Set it to your JDK

AI-assisted analysis of dotnet/maui@f377ff1c5e (2026-08-13). Data as JSON: /api/errors/e504c0f978171efc. Report an issue: GitHub.