don't catch IOError to produce backtrace that points at cause

osc/babysitter.py

@@ -134,10 +134,6 @@ def run(prg):
         print >>sys.stderr, e.msg
         return 1
 
-    except IOError, e:
-        print >>sys.stderr, e
-        return 1
-
     except AttributeError, e:
         print >>sys.stderr, e
         return 1

osc/fetch.py

@@ -335,10 +335,9 @@ def verify_pacs(pac_list, key_list):
             except Exception, e:
                 failed = True
                 print pkg, ':', e
-    except Exception, e:
-        print str(e)
+    except:
         checker.cleanup()
-        sys.exit(1)
+        raise
 
     if failed:
         checker.cleanup()