rsalveti@evasys:/tmp/snappy/new/stable$ sudo ubuntu-device-flash core 15.04 --channel stable --oem beagleblack --install=hello-world --enable-ssh --output ubuntu-15.04-snappy-armhf-bbb.img
Determining oem configuration
Starting download of beagleblack
280.75 KB / 280.75 KB [====================================================================================================================================================================================================================================] 100.00 % 69.87 KB/s 
Done
Fetching information from server...
Downloading and setting up...
Installing beagleblack
Starting download of beagleblack
280.75 KB / 280.75 KB [====================================================================================================================================================================================================================================] 100.00 % 96.10 KB/s 
Done
Installing hello-world
Starting download of hello-world
21.55 KB / 21.55 KB [======================================================================================================================================================================================================================================] 100.00 % 77.02 KB/s 
Done
panic: unable to unmount dir for image: umount: /tmp/diskimage898827634/system: target is busy
        (In some cases useful info about processes that
         use the device is found by lsof(8) or fuser(1).)


goroutine 1 [running, locked to thread]:
launchpad.net/goget-ubuntu-touch/diskimage.(*CoreUBootImage).Unmount(0xc2080e4420, 0x0, 0x0)
	/build/buildd/goget-ubuntu-touch-0.23/obj-x86_64-linux-gnu/src/launchpad.net/goget-ubuntu-touch/diskimage/core_uboot.go:115 +0x67d
main.func·006()
	/build/buildd/goget-ubuntu-touch-0.23/obj-x86_64-linux-gnu/src/launchpad.net/goget-ubuntu-touch/ubuntu-device-flash/core.go:341 +0x120
main.(*CoreCmd).setup(0xcf0920, 0x7efd782dbd80, 0xc2080e4420, 0xc2082a0720, 0x3, 0x0, 0x0)
	/build/buildd/goget-ubuntu-touch-0.23/obj-x86_64-linux-gnu/src/launchpad.net/goget-ubuntu-touch/ubuntu-device-flash/core.go:405 +0x1753
main.func·004(0x0, 0x0)
	/build/buildd/goget-ubuntu-touch-0.23/obj-x86_64-linux-gnu/src/launchpad.net/goget-ubuntu-touch/ubuntu-device-flash/core.go:280 +0x171
main.(*CoreCmd).Execute(0xcf0920, 0xc20800a0b0, 0x1, 0xb, 0x0, 0x0)
	/build/buildd/goget-ubuntu-touch-0.23/obj-x86_64-linux-gnu/src/launchpad.net/goget-ubuntu-touch/ubuntu-device-flash/core.go:285 +0x20d9
github.com/jessevdk/go-flags.(*Parser).ParseArgs(0xc2080566c0, 0xc20800a000, 0xb, 0xb, 0x0, 0x0, 0x0, 0x0, 0x0)
	/build/buildd/goget-ubuntu-touch-0.23/obj-x86_64-linux-gnu/src/github.com/jessevdk/go-flags/parser.go:241 +0x8b8
main.main()
	/build/buildd/goget-ubuntu-touch-0.23/obj-x86_64-linux-gnu/src/launchpad.net/goget-ubuntu-touch/ubuntu-device-flash/main.go:62 +0x3ac

goroutine 5 [syscall]:
os/signal.loop()
	/usr/lib/go/src/os/signal/signal_unix.go:21 +0x1f
created by os/signal.init·1
	/usr/lib/go/src/os/signal/signal_unix.go:27 +0x35

goroutine 6 [chan receive]:
launchpad.net/snappy/partition.func·005()
	/build/buildd/goget-ubuntu-touch-0.23/obj-x86_64-linux-gnu/src/launchpad.net/snappy/partition/partition.go:270 +0x52
created by launchpad.net/snappy/partition.setupSignalHandler
	/build/buildd/goget-ubuntu-touch-0.23/obj-x86_64-linux-gnu/src/launchpad.net/snappy/partition/partition.go:275 +0x21e

goroutine 17 [syscall, locked to thread]:
runtime.goexit()
	/usr/lib/go/src/runtime/asm_amd64.s:2232 +0x1

goroutine 58 [chan receive]:
main.func·003()
	/build/buildd/goget-ubuntu-touch-0.23/obj-x86_64-linux-gnu/src/launchpad.net/goget-ubuntu-touch/ubuntu-device-flash/core.go:261 +0x1e8
created by main.(*CoreCmd).Execute
	/build/buildd/goget-ubuntu-touch-0.23/obj-x86_64-linux-gnu/src/launchpad.net/goget-ubuntu-touch/ubuntu-device-flash/core.go:264 +0x2015