diff --git a/error.py b/error.py
new file mode 100644
index 0000000..e3cf41c
--- /dev/null
+++ b/error.py
@@ -0,0 +1,66 @@
+#
+# Copyright (C) 2008 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+class ManifestParseError(Exception):
+  """Failed to parse the manifest file.
+  """
+
+class EditorError(Exception):
+  """Unspecified error from the user's text editor.
+  """
+
+class GitError(Exception):
+  """Unspecified internal error from git.
+  """
+  def __init__(self, command):
+    self.command = command
+
+  def __str__(self):
+    return self.command
+
+class ImportError(Exception):
+  """An import from a non-Git format cannot be performed.
+  """
+  def __init__(self, reason):
+    self.reason = reason
+
+  def __str__(self):
+    return self.reason
+
+class UploadError(Exception):
+  """A bundle upload to Gerrit did not succeed.
+  """
+  def __init__(self, reason):
+    self.reason = reason
+
+  def __str__(self):
+    return self.reason
+
+class NoSuchProjectError(Exception):
+  """A specified project does not exist in the work tree.
+  """
+  def __init__(self, name=None):
+    self.name = name
+
+  def __str__(self):
+    if self.Name is None:
+      return 'in current directory'
+    return self.name
+
+class RepoChangedException(Exception):
+  """Thrown if 'repo sync' results in repo updating its internal
+     repo or manifest repositories.  In this special case we must
+     use exec to re-execute repo with the new code and manifest.
+  """