Comment 1 for bug 1437910

I have Ubuntu version 12.04 and me too I'm not able to take screen shots....
If I start adb server phablet-screenshot command will trace "E: Device '' is not supported."

~$ sudo adb start-server
~$ phablet-screenshot test.png
E: Device '' is not supported.

With debug option....

~$ phablet-screenshot -d test.png
+ shift
+ true
+ shift
+ break
+ [ 1 -eq 0 ]
+ DST=test.png
+ check_prerequisites
+ okay=1
+ pkgs=android-tools-adb imagemagick
+ dpkg-query+ grep ok installed
 -W -f ${Status}\t${Package}\n android-tools-adb
+ dpkg-query -W -f ${Status}\t${Package}\n imagemagick
+ grep ok installed
+ [ 1 -ne 1 ]
+ sf_is_running
+ adb shell pidof surfaceflinger
error: closed
+ sf=* daemon not running. starting it now on port 5037 *
* daemon started successfully *
+ [ -z * daemon not running. starting it now on port 5037 *
* daemon started successfully * ]
+ echo I: surfaceflinger detected
I: surfaceflinger detected
+ return 0
+ screenshot_sf
+ echo I: Capturing screenshot with screencap ...
I: Capturing screenshot with screencap ...
+ capfile=screencap.png
+ adb shell /system/bin/screencap /tmp/screencap.png
error: closed
+ cleanup
+ [ -d /tmp/phablet-screenshot.F6exJa ]
+ rm -Rf /tmp/phablet-screenshot.F6exJa
matti@casa:~$ phablet-screenshot -d test.png
+ shift
+ true
+ shift
+ break
+ [ 1 -eq 0 ]
+ DST=test.png
+ check_prerequisites
+ okay=1
+ pkgs=android-tools-adb imagemagick
+ dpkg-query+ grep ok installed
 -W -f ${Status}\t${Package}\n android-tools-adb
+ dpkg-query -W -f ${Status}\t${Package}\n imagemagick
+ grep ok installed
+ [ 1 -ne 1 ]
+ sf_is_running
+ adb shell pidof surfaceflinger
+ sf=
+ [ -z ]
+ return 1
+ depth=8
+ [ -z ]
+ get_mode
+ + cutadb -d: shell -f2 head
 -1+ cut -d p -f1
 /sys/devices/virtual/graphics/fb0/modes
+ size= cannot o
+ echo cannot o
+ grep -qE ^[0-9]+x[0-9]+$
+ get_device
+ adb shell getprop ro.cm.device
+ device=
+ echo
+ tr -d \r
+ device=
+ size=
+ echo
+ size=
+ get_device
+ adb shell getprop ro.cm.device
+ device=
+ echo
+ tr -d \r
+ device=
+ [ -z ]
+ echo E: Device '' is not supported.
E: Device '' is not supported.
+ exit 1
+ cleanup
+ [ -d /tmp/phablet-screenshot.5RQBNj ]
+ rm -Rf /tmp/phablet-screenshot.5RQBNj