adb backup hangs and never finishes (Linux) Whenever I run adb backup for a full backup, it never finishes. In Terminal, the command hangs indefinitely, and on the device, the backup cycles through a few apps before hanging on one (more about that at the end of this question).
After executing adb backup, the backup file on the PC slowly increases in size, but after a while it stops growing. I've let it sit at this point for an hour without any change in the size of the file.
I've tried running adb backup 3 different ways ($ab is just the name of the backup file):
adb backup -f &quot;${ab}&quot; -apk -obb -noshared -all -system
adb backup -f &quot;${ab}&quot; -apk -obb -shared -all -system
adb backup -f &quot;${ab}&quot; -noapk -noobb -noshared -all

Not even the last one works. I also tried setting up a desktop backup password under here:
Settings &gt; Developer Options &gt; Desktop backup password

This didn't help either.
This problem occurs with two different devices, both rooted. Both devices run on Android 5.1.1, so maybe it's a bug with this version of Android? It didn't work on 5.1 either. One of the devices is a Nexus 6 using the official Android 5.1.1 image, so it's not a bug with a custom ROM.
The last few times I tried running adb backup on the Nexus 6, I noticed that it started hanging on the same app each time: Titanium Backup. I don't know if this has always been the case; I just noticed it recently.
Does anyone have any suggestions? Also, do any other Linux users have this problem too? If so, it's likely a bug within the adb package.
EDIT
After running adb backup again, it worked! I'm guessing it's because I upgraded my Nexus device's firmware to a slightly newer version: from LMY47Z to LMY48I (both are Android 5.1.1). Maybe it was a bug with the earlier 5.1.1 build, the one before the &quot;Stagefright&quot; fix was added.
Settings &rarr; Apps &rarr; Titanium Backup &rarr; Force Stop may allow the ADB backup to continue and finish.