Logging information during task execution

The logging utilities provided by BitBake are handy for tracing the code execution path. BitBake provides logging functions for use in Python and Shell Script code, described as follows:

• Python: For use within Python functions, BitBake supports several log levels such as bb.fatal, bb.error, bb.warn, bb.note, bb.plain, and bb.debug.
• Shell Script: For use in Shell Script functions, the same set of log levels exists and is accessed with a similar syntax: bbfatal, bberror, bbwarn, bbnote, bbplain, and bbdebug.

These logging functions are very similar to each other but have minor differences, described as follows:

• bb.fatal and bbfatal: These have the highest priority for logging messages as they print the message and terminate the processing. They cause the build to be interrupted.
• bb.error and bberror: These display an error but do not force the build to stop.
• bb.warn and bbwarn: These warn the users about something...