[jhbuild] sysdeps: use PyGObject when possible for main loop

[Christian Hergert <chergert src gnome org>]

commit 54c8e37b1e0739a7d5094b28735187b4e945bf49
Author: Christian Hergert <chergert redhat com>
Date:   Fri Jan 5 14:07:21 2018 -0800

    sysdeps: use PyGObject when possible for main loop
    
    If we have gi.repository.GLib, it is suitable (API-wise) to create
    a GMainLoop that integrates the same as the old glib module.
    
    This fixes installation on Fedora systems that don't have the old
    glib python module available.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=792255

 jhbuild/utils/systeminstall.py |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/jhbuild/utils/systeminstall.py b/jhbuild/utils/systeminstall.py
index 1c53b10..0399621 100644
--- a/jhbuild/utils/systeminstall.py
+++ b/jhbuild/utils/systeminstall.py
@@ -254,7 +254,10 @@ class PKSystemInstall(SystemInstall):
             try:
                 import glib
             except:
-                raise SystemExit(_('Error: python-gobject package not found.'))
+                try:
+                    from gi.repository import GLib as glib
+                except:
+                    raise SystemExit(_('Error: python-gobject package not found.'))
             self._loop = glib.MainLoop()
         if self._sysbus is None:
             try: