[pitivi] pipeline: Make exceptions return useful messages

[Edward Hervey <edwardrv src gnome org>]

commit e73b34d72eb336508ab84d0a632eb4a1af3e6d53
Author: Edward Hervey <bilboed bilboed com>
Date:   Sat Jul 10 13:59:05 2010 +0200

    pipeline: Make exceptions return useful messages

 pitivi/pipeline.py |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/pitivi/pipeline.py b/pitivi/pipeline.py
index d6e8507..f8f33d7 100644
--- a/pitivi/pipeline.py
+++ b/pitivi/pipeline.py
@@ -525,7 +525,7 @@ class Pipeline(Signallable, Loggable):
             return bin_entry.bin
 
         if not automake:
-            raise PipelineError()
+            raise PipelineError("Couldn't get an existing Bin for Factory %r" % factory)
 
         bin = stream_entry.bin = factory.makeBin(stream)
         stream_entry.bin_use_count += 1
@@ -660,7 +660,7 @@ class Pipeline(Signallable, Loggable):
         stream_entry = self._getStreamEntryForFactoryStream(factory, stream)
 
         if stream_entry.tee_use_count == 0:
-            raise PipelineError()
+            raise PipelineError("Tee is already unused from factory %r" % factory)
 
         stream_entry.tee_use_count -= 1
         if stream_entry.tee_use_count == 0:
@@ -750,11 +750,11 @@ class Pipeline(Signallable, Loggable):
         @raise PipelineError: If the Pipeline isn't in NULL or READY.
         """
         if not isinstance(factory, SinkFactory):
-            raise PipelineError()
+            raise PipelineError("Attempting to release a queue for a non-sink factory (%r)" % factory)
 
         stream_entry = self._getStreamEntryForFactoryStream(factory, stream)
         if stream_entry.queue is None:
-            raise PipelineError()
+            raise PipelineError("Couldn't find Queue for Stream/Factory")
 
         stream_entry.queue_use_count -= 1
         if stream_entry.queue_use_count == 0: