Stop using bare except: statements

It is almost never a good idea to catch all exceptions, and then do
nothing about them. This patch logs all caught exceptions so that the
user has some possibilty to debug what is happening.

Also, make ./check check for bare excepts and fail the test suite if it
finds anything.

1 files changed, 12 insertions, 7 deletions

diff --git a/morphlib/mountableimage.py b/morphlib/mountableimage.py
index 3d29a516..f767228a 100644
--- a/morphlib/mountableimage.py
+++ b/morphlib/mountableimage.py
@@ -15,6 +15,7 @@
 
 
 import cliapp
+import logging
 import os
 import tempfile
 import gzip
@@ -45,7 +46,9 @@ class MountableImage(object): # pragma: no cover
                 infh = gzip.open(path, "rb")
                 morphlib.util.copyfileobj(infh, outfh)
                 infh.close()
-        except:
+        except BaseException, e:
+            logging.error('Caught exception: %s' % str(e))
+            logging.info('Removing temporary file %s' % self.temp_path)
             os.unlink(self.temp_path)
             raise
         self.app.status(msg='  Mounting image at %(path)s',
@@ -62,17 +65,19 @@ class MountableImage(object): # pragma: no cover
                         chatty=True)
         try:
             morphlib.fsutils.unmount(self.app.runcmd, mount_point)
-        except:
-            pass
+        except BaseException, e:
+            logging.info('Ignoring error when unmounting: %s' % str(e))
         try:
             morphlib.fsutils.undo_device_mapping(self.app.runcmd, path)
-        except:
-            pass
+        except BaseException, e:
+            logging.info(
+                'Ignoring error when undoing device mapping: %s' % str(e))
         try:
             os.rmdir(mount_point)
             os.unlink(path)
-        except:
-            pass
+        except BaseException, e:
+            logging.info(
+                'Ignoring error when removing temporary files: %s' % str(e))
 
     def __enter__(self):
         return self.setup(self.artifact_path)