when running 'android update', sometimes the program returns an error on
stderr without giving a !=0 errorcode.
This patch detects such an error, and throws a proper BuildException
(in my case, it printed the following to stderr:
Error: The project either has no target set or the target is invalid.
Please provide a --target to the 'android update' command.)
The prepare_source method runs commands and everything, but the -v
option gives no insight into what is happening in this method.
This patch adds some verbose output, useful to discover why/where a scan
fails
