--- a/piecrust/processing/base.py	Tue Feb 03 08:20:30 2015 -0800
+++ b/piecrust/processing/base.py	Tue Feb 03 08:21:43 2015 -0800
@@ -9,7 +9,8 @@
 from piecrust.chefutil import format_timed
 from piecrust.processing.records import (
         ProcessorPipelineRecordEntry, TransitionalProcessorPipelineRecord,
-        FLAG_PROCESSED, FLAG_OVERRIDEN, FLAG_BYPASSED_STRUCTURED_PROCESSING)
+        FLAG_PREPARED, FLAG_PROCESSED, FLAG_OVERRIDEN,
+        FLAG_BYPASSED_STRUCTURED_PROCESSING)
 from piecrust.processing.tree import (
         ProcessingTreeBuilder, ProcessingTreeRunner,
         ProcessingTreeError, ProcessorError,
@@ -20,6 +21,9 @@
 logger = logging.getLogger(__name__)
 
 
+re_ansicolors = re.compile('\033\\[\d+m')
+
+
 PRIORITY_FIRST = -1
 PRIORITY_NORMAL = 0
 PRIORITY_LAST = 1
@@ -105,6 +109,14 @@
         raise NotImplementedError()
 
 
+class ExternalProcessException(Exception):
+    def __init__(self, stderr_data):
+        self.stderr_data = stderr_data
+
+    def __str__(self):
+        return self.stderr_data
+
+
 class ProcessingContext(object):
     def __init__(self, base_dir, mount_info, job_queue, record=None):
         self.base_dir = base_dir
@@ -360,9 +372,10 @@
         try:
             builder = ProcessingTreeBuilder(processors)
             tree_root = builder.build(rel_path)
+            record_entry.flags |= FLAG_PREPARED
         except ProcessingTreeError as ex:
             msg = str(ex)
-            logger.error("Error processing %s: %s" % (rel_path, msg))
+            logger.error("Error preparing %s:\n%s" % (rel_path, msg))
             while ex:
                 record_entry.errors.append(str(ex))
                 ex = ex.__cause__
@@ -396,9 +409,10 @@
             msg = str(ex)
             if isinstance(ex, ProcessorError):
                 msg = str(ex.__cause__)
-            logger.error("Error processing %s: %s" % (rel_path, msg))
+            logger.error("Error processing %s:\n%s" % (rel_path, msg))
             while ex:
-                record_entry.errors.append(str(ex))
+                msg = re_ansicolors.sub('', str(ex))
+                record_entry.errors.append(msg)
                 ex = ex.__cause__
             return False