> Description of problem:
If I do "virt-manager --h" command from ssh shell, I see the following error on the screen. If I do this command from console,
it prints the correct print output

[root@blade7-rhel6 ~]# virt-manager --h
Traceback (most recent call last):
File "/usr/share/virt-manager/virt-manager.py", line 455, in <module>
main()
File "/usr/share/virt-manager/virt-manager.py", line 341, in main
import gtk
File "/usr/lib64/python2.6/site-packages/gtk-2.0/gtk/__init__.py", line 64, in <module>
_init()
File "/usr/lib64/python2.6/site-packages/gtk-2.0/gtk/__init__.py", line 52, in _init
_gtk.init_check()
RuntimeError: could not open display 

> Version-Release number of selected component (if applicable):
- Red Hat Enterprise Linux 6.1

> Steps to Reproduce:
- Using RHEL 6.1 and ssh with "-X":
[wr41th@arkham ~]$ ssh root.1.101 -X
root.1.101's password: 

[root@host01 ~]# virt-manager -h
Usage: virt-manager.py [options]

Options:
  --version             show program's version number and exit
  -h, --help            show this help message and exit
  --profile=FILE        Generate runtime performance profile stats
  -c URI, --connect=URI
                        Connect to hypervisor at URI
  --debug               Print debug output to stdout (implies --no-fork)
  --no-dbus             Disable DBus service for controlling UI
  --no-fork             Don't fork into background on startup
  --no-conn-autostart   Do not autostart connections
  --show-domain-creator
                        Create a new virtual machine
  --show-domain-editor=UUID
                        Edit a domain configuration
  --show-domain-performance=UUID
                        Show a domain performance
  --show-domain-console=UUID
                        Show a domain console
  --show-host-summary   Show a host summary

- Using RHEL 6.1 and ssh without "-X":
[root@host01 ~]# virt-manager -h
ERROR:root:could not open display
Traceback (most recent call last):
  File "/usr/share/virt-manager/virt-manager.py", line 413, in <module>
    main()
  File "/usr/share/virt-manager/virt-manager.py", line 285, in main
    import gtk
  File "/usr/lib64/python2.6/site-packages/gtk-2.0/gtk/__init__.py", line 64, in <module>
    _init()
  File "/usr/lib64/python2.6/site-packages/gtk-2.0/gtk/__init__.py", line 52, in _init
    _gtk.init_check()
RuntimeError: could not open display
Traceback (most recent call last):
  File "/usr/share/virt-manager/virt-manager.py", line 420, in <module>
    _show_startup_error(str(run_e), "".join(traceback.format_exc()))
  File "/usr/share/virt-manager/virt-manager.py", line 61, in _show_startup_error
    import gtk
  File "/usr/lib64/python2.6/site-packages/gtk-2.0/gtk/__init__.py", line 64, in <module>
    _init()
  File "/usr/lib64/python2.6/site-packages/gtk-2.0/gtk/__init__.py", line 52, in _init
    _gtk.init_check()
RuntimeError: could not open display

- Using RHEL 5.5 and ssh without "-X":
[root@host02 ~]# virt-manager -h
usage: virt-manager.py [options]

options:
  -h, --help            show this help message and exit
  --profile=FILE        Generate runtime performance profile stats
  -c URI, --connect=URI
                        Connect to hypervisor at URI
  --debug               Print debug output to stdout (requires --no-fork)
  --no-dbus             Disable DBus service for controlling UI
  --no-fork             Don't fork into background on startup
  --no-conn-autostart   Do not autostart connections
  --show-domain-creator
                        Create a new virtual machine
  --show-domain-editor=UUID
                        Edit a domain configuration
  --show-domain-performance=UUID
                        Show a domain performance
  --show-domain-console=UUID
                        Show a domain console
  --show-host-summary   Show a host summary
  
> Additional info:

The error happens because the command line arguments are being parsed after the main () tries to run the GTK.

There is a difference in main() statement.

- RHEL5 in /usr/share/virt-manager/virt-manager.py
--snip--
# Run me!
def main():
    setup_i18n()
    setup_pypath()

    (options, ignore) = parse_commandline()
    setup_logging(options.debug)

    # Urgh, pygtk merely logs a warning when failing to open
    # the X11 display connection, and lets everything carry
    # on as if all were fine. Ultimately bad stuff happens,
    # so lets catch it here & get the hell out...
    import warnings
    warnings.filterwarnings('error', module='gtk')
    try:
--/snip--


- RHEL6 in /usr/share/virt-manager/virt-manager.py
--snip--
# Run me!
def main():
    setup_i18n()
    setup_pypath()

    # Urgh, pygtk merely logs a warning when failing to open
    # the X11 display connection, and lets everything carry
    # on as if all were fine. Ultimately bad stuff happens,
    # so lets catch it here & get the hell out...
    import warnings
    warnings.filterwarnings('error', module='gtk')
    try:
        import gobject

        # Set program name for gnome shell (before importing gtk, which
--/snip--


We can see in RHEL5 virt-manager.py there is the following line getting the command line arguments before to start the GTk. 

    (options, ignore) = parse_commandline()


In RHEL6 this line is after: 

        import gtk
    except Warning, e:
        # ...the risk is we catch too much though
        # Damned if we do, damned if we dont :-)(
        raise RuntimeError(_("Unable to initialize GTK: %s") % str(e))
    warnings.resetwarnings()

    (options, ignore) = parse_commandline()
    setup_logging(options.debug)