bake: Better error handling for the processing pipeline. Pipeline jobs now keep track of whether they've seen any errors. This is aggregated into an overall "success" flag for the processing record. Also, jobs keep going as long as there's no critical (i.e. internal) failure happening. Errors raised by processors are also better tracked: the actual processor that failed, along with the input file, are tracks in the processing record. The `bake` command returns a failure exit code if processing saw any error.

import sys
import logging


def pytest_runtest_setup(item):
    pass


def pytest_addoption(parser):
    parser.addoption('--log-debug', action='store_true',
            help="Sets the PieCrust logger to output debug info to stdout.")


def pytest_configure(config):
    if config.getoption('--log-debug'):
        hdl = logging.StreamHandler(stream=sys.stdout)
        logging.getLogger('piecrust').addHandler(hdl)
        logging.getLogger('piecrust').setLevel(logging.DEBUG)