I had this same problem and I noticed the following while booting:
init: cannot find '/sbin/adbd', disabling 'adbd'
It seems during early boot the adb daemon was running for a while in the emulator image, and then in stopped working:
$ adb devices List of devices attached emulator-5554 offline
$ adb devices List of devices attached
I had this same problem and I noticed the following while booting:
init: cannot find '/sbin/adbd', disabling 'adbd'
It seems during early boot the adb daemon was running for a while in the emulator image, and then in stopped working:
$ adb devices
List of devices attached
emulator-5554 offline
$ adb devices
List of devices attached