Android adb “Unable to open sync connection!”

Question

I can run and debug my Android app on my phone just fine, most of the time. Then, seemingly randomly, when I try to run or debug my app from Eclipse, the Console in Eclipse says:

[2010-10-12 09:36:48 - myapp] Android Launch!
[2010-10-12 09:36:48 - myapp] adb is running normally.
[2010-10-12 09:36:48 - myapp] Performing com.mycompany.myapp.MyActivity activity launch
[2010-10-12 09:36:48 - myapp] Automatic Target Mode: using device 'HT01TP800561'
[2010-10-12 09:36:48 - myapp] Uploading myapp.apk onto device 'HT01TP800561'
[2010-10-12 09:36:48 - myapp] Failed to upload myapp.apk on device 'HT01TP800561'
[2010-10-12 09:36:48 - myapp] java.io.IOException: Unable to open sync connection!
[2010-10-12 09:36:48 - myapp] Launch canceled!

• Retry: doesn't help, same messages.
• Restart Eclipse: doesn't help.
• Restart adb (adb kill-server && adb start-server): no errors, doesn't help.
• Reconnect the phone: sometimes helps.
• Reboot the computer: kind of drastic, haven't tried this yet.

Using Ubuntu 10.4, Eclipse Galileo 3.5.2, Android SDK 7, ADT plugin 0.9.6, Nexus One, Android 2.2.1.

Any bright ideas?

Answer 1

What helps for me is the following: ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

If you are debugging on AndroidX86 (or otherwise have root access to your Android developer machine) Kill the "adbd" process.. and let it restart.

e.g.

[On Android VM]

• kill adbd (e.g. kill `ps a| grep adbd | awk ' { print $2 } ' `)
• /sbin/adbd will restart automatically

[On DEV station]

• [dev station] ./adb disconnect
• [dev station] ./adb connect

If you don't have root, probably toggling USB debugging, rebooting, etc could also help. As it also restarts adbd ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Answer 2

The solution is likely to run on your android phone (on local terminal or ssh terminal): $ stop adbd; start adb

I don't like overkill solutions like rebooting hte phone... and this is usually not needed under Linux. I experienced the same problem when connecting over Wifi, so USB is maybe not responsible at all. Reading the answer from user655489, I got the idea to run lsof, and then lsof | grep adbd | wc -l => I think I had over many sockets open with all FD from 0 to 1023 in use... how suspicious.

I ran killall adbd, then restarted adbd per How can I connect to Android with ADB over TCP? And the problem was gone.

The cause is that, at least when debugging and having to kill my non-working apps, that several of the sockets never get closed.

Answer 3

I have had the same problem and restarting ADB wouldn't work for me. Sometimes rebooting my phone worked but not always, I was unable to program for about a week because of this glitch and I think I finally found a workaround! :-D

First of all, kill every program running on your phone. Having some kind of taskmanager makes this a quick task, otherwise you'll have to manually kill them all one at a time.

If that doesn't fix it, you will need to go to your phone settings, then go to "Applications", then go to "Running services", and kill every service in there. I'm using a Droid Incredible and I have yet to have this not work for me. :-)

So, the short answer is, kill all apps, and all services.

Also, keep in mind, you will need to close, and re-open eclipse to see if this fix has worked for you. I hope this works for you, I know it did for me! :-D

Answer 4

I have been experiencing this problem very often (I mean like every second time I launched Debug). I was using a rather long USB cable. I switched to the original HTC USB cable which is short and the problem was gone!

Answer 5

I have been having the same problem when I have the phone connected through my keyboard's USB hub. IT went away when I connected straight to the computer's USB port.

Answer 6

I experienced this problem when my USB cable was connected to PC via keyboard USB :O. When I connected it to PC directly my problem solved.

I hope this works.

Enjoy!