Output component level error information

[elikoga]

batou/src/batou/component.py

Lines 232 to 251 in 10caa65

	self.parent = parent
	self.workdir = parent.workdir
	self.sub_components = []
	if self.parent is self.root:
	self._overrides(self.root.overrides)
	# Fix up attributes that have been set through the constructor.
	for k, v in list(self.__dict__.items()):
	attribute = getattr(self.__class__, k, None)
	if not isinstance(attribute, Attribute):
	continue
	# Setting it using the mutator causes conversions and our
	# special attribute handling to catch up.
	setattr(self, k, v)
	with self.chdir(self.defdir):
	self.configure()
	self += self._get_platform()
	self._platform_component = self._
	self.__setup_event_handlers__()
	self._prepared = True

If we try catch and rethrow errors in this function, we can enrich them with their tracebacks more meaningfully than having to throw a UnknownComponentConfigurationError as here

batou/src/batou/environment.py

Lines 509 to 517 in 10caa65

	except Exception as e:
	# An unknown exception which we have to work harder
	# to report gracefully.
	ex_type, ex, tb = sys.exc_info()
	exceptions.append(
	UnknownComponentConfigurationError.from_context(
	root, e, tb
	)
	)

Which says that this may indicate a bug in batou. But we don't want to have the message in a few cases (for example, user errors when using the templating mechanism (see #417)