Trying to fix unending transformations on start() error.

bonobo/util/errors.py

@@ -0,0 +1,30 @@
+import sys
+
+from bonobo.structs.bags import ErrorBag
+
+
+def is_error(bag):
+    return isinstance(bag, ErrorBag)
+
+
+def print_error(exc, trace, context=None, prefix=''):
+    """
+    Error handler. Whatever happens in a plugin or component, if it looks like an exception, taste like an exception
+    or somehow make me think it is an exception, I'll handle it.
+
+    :param exc: the culprit
+    :param trace: Hercule Poirot's logbook.
+    :return: to hell
+    """
+
+    from colorama import Fore, Style
+    print(
+        Style.BRIGHT,
+        Fore.RED,
+        '\U0001F4A3 {}{}{}'.format((prefix + ': ') if prefix else '', type(exc).__name__,
+                                   ' in {!r}'.format(context) if context else ''),
+        Style.RESET_ALL,
+        sep='',
+        file=sys.stderr,
+    )
+    print(trace)