I built the Android AOSP tree for the mako device successfully on my Ubuntu 14.04 LTS desktop with the '. build/envset.sh', 'lunch mako-userdebug', and 'make -j4' series of commands. I tried to run it in the emulator by following the Google-provided instructions (i.e. typing the 'emulator' command in a terminal right after the build is complete) but it does not work. The emulator starts up but is stuck on a black screen. I noticed the following warning/errors while the emulator starts up:
emulator: control console listening on port 5554, ADB on port 5555
emulator: can't connect to ADB server: Transport endpoint is not connected (errno = 107)
Any help in resolving this error is greatly appreciated.