Fix a bug introduced in 4e58b51b

The error function main.py used for outputing errors has been removed
and the code was not updated to use the error method of SimpleOutput
output class.
Also did a minor cleanup: git_os_class function was renamed to os_cls

image_creator/main.py

@@ -39,7 +39,7 @@ from image_creator.disk import Disk
 from image_creator.util import get_command, FatalError, MD5
 from image_creator.output.cli import SilentOutput, SimpleOutput, \
                                      OutputWthProgress
-from image_creator.os_type import get_os_class
+from image_creator.os_type import os_cls
 from image_creator.kamaki_wrapper import Kamaki
 import sys
 import os
@@ -187,8 +187,8 @@ def image_creator():
         dev = disk.get_device(snapshot)
         dev.mount()
 
-        osclass = get_os_class(dev.distro, dev.ostype)
-        image_os = osclass(dev.root, dev.g, out)
+        cls = os_cls(dev.distro, dev.ostype)
+        image_os = cls(dev.root, dev.g, out)
         out.output()
 
         for sysprep in options.disabled_syspreps:
@@ -283,10 +283,8 @@ def main():
         ret = image_creator()
         sys.exit(ret)
     except FatalError as e:
-        if sys.stdout.isatty():
-            error(e)
-        else:
-            error(e, True, False)
+        colored = sys.stderr.isatty()
+        SimpleOutput(colored).error(e)
         sys.exit(1)
 
 

image_creator/os_type/__init__.py

@@ -37,7 +37,7 @@ import textwrap
 import re
 
 
-def get_os_class(distro, osfamily):
+def os_cls(distro, osfamily):
     module = None
     classname = None
     try: