clarify error for duplicate file names in a task

doc/conf.py

@@ -55,9 +55,9 @@
 # built documents.
 #
 # The short X.Y version.
-version = u'shortlist'
+version = u'0.0.0.dev0'
 # The full version, including alpha/beta/rc tags.
-release = u'shortlist'
+release = u'0.0.0.dev0'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.

utils/loomengine_utils/exceptions.py

@@ -16,6 +16,9 @@ class ResourceCountError(LoomengineUtilsError):
 class ExportManagerError(LoomengineUtilsError):
     pass
 
+class FileAlreadyExistsError(ExportManagerError):
+    pass
+
 class FileUtilsError(LoomengineUtilsError):
     pass
 

utils/loomengine_utils/export_manager.py

@@ -4,7 +4,8 @@
 import os
 import yaml
 
-from .exceptions import LoomengineUtilsError, ExportManagerError
+from .exceptions import LoomengineUtilsError, ExportManagerError, \
+    FileAlreadyExistsError
 from .file_utils import File
 
 logger = logging.getLogger(__name__)
@@ -68,7 +69,7 @@ def export_file(self, data_object, destination_directory=None,
             destination = File(
                 destination_file_url, self.storage_settings, retry=retry)
             if destination.exists():
-                raise ExportManagerError(
+                raise FileAlreadyExistsError(
                     'File already exists at %s' % destination_file_url)
             logger.info('...copying file to %s' % (
                 destination.get_url()))

worker/loomengine_worker/task_monitor.py

@@ -20,9 +20,10 @@
 import uuid
 
 from loomengine_utils import execute_with_retries
+from loomengine_utils.connection import Connection
+from loomengine_utils.exceptions import FileAlreadyExistsError
 from loomengine_utils.export_manager import ExportManager
 from loomengine_utils.import_manager import ImportManager
-from loomengine_utils.connection import Connection
 from loomengine_worker.outputs import TaskAttemptOutput
 from loomengine_worker.inputs import TaskAttemptInput
 
@@ -160,6 +161,12 @@ def _copy_inputs(self):
         try:
             for input in self.task_attempt['inputs']:
                 TaskAttemptInput(input, self).copy()
+        except FileAlreadyExistsError as e:
+            error = self._get_error_text(e)
+            self._report_system_error(
+                detail='Copying inputs failed because file already exists. '\
+                'Are there multiple inputs with the same name? %s' % error)
+            raise
         except Exception as e:
             error = self._get_error_text(e)
             self._report_system_error(detail='Copying inputs failed. %s' % error)