Auto install script fails on Nexus 5

[SafwatHalaby]

___./android-install.sh 
remount of system failed: Permission denied
remount failed
failed to copy './busybox-android' to '/data/busybox': Permission denied
su
mount -oremount,rw /system
/data/busybox mount -oremount,rw /system
/data/busybox rm /data/busybox
exit
exit

shell@hammerhead:/ $ su
mount -oremount,rw /system
/data/busybox mount -oremount,rw /system
/data/busybox rm /data/busybox
exit
exit

[Rosalie241]

try su-C sh android-install.sh