diff --git a/src/calibre/devices/scanner.py b/src/calibre/devices/scanner.py
index 96d61dcbd2..6657a2f26a 100644
--- a/src/calibre/devices/scanner.py
+++ b/src/calibre/devices/scanner.py
@@ -58,8 +58,8 @@ class DeviceScanner(object):
     def __init__(self, *args):
         if isosx and osx_scanner is None:
             raise RuntimeError('The Python extension usbobserver must be available on OS X.')
-        if not (isosx or iswindows) and not os.access(_DEVICES, os.R_OK):
-            raise RuntimeError('DeviceScanner requires %s to work.'%_DEVICES)
+        if not (isosx or iswindows) and (not os.access(_DEVICES, os.R_OK) and not libusb.has_library):
+            raise RuntimeError('DeviceScanner requires %s or libusb to work.'%_DEVICES)
         self.scanner = win_scanner if iswindows else osx_scanner if isosx else linux_scanner
         self.devices = []
 
diff --git a/src/calibre/web/feeds/news.py b/src/calibre/web/feeds/news.py
index 0aa2ac25f8..db0a06886a 100644
--- a/src/calibre/web/feeds/news.py
+++ b/src/calibre/web/feeds/news.py
@@ -808,6 +808,9 @@ class BasicNewsRecipe(Recipe):
         '''
         Create a generic cover for recipes that dont have a cover
         '''
+        from calibre.gui2 import is_ok_to_use_qt
+        if not is_ok_to_use_qt():
+            return False
         from calibre.gui2 import images_rc # Needed for access to logo
         images_rc
         if QApplication.instance() is None: QApplication([])
@@ -868,6 +871,7 @@ class BasicNewsRecipe(Recipe):
         else:
             cover_file.write(renderer.data)
             cover_file.flush()
+        return True
 
 
     def create_opf(self, feeds, dir=None):
@@ -892,8 +896,8 @@ class BasicNewsRecipe(Recipe):
         cpath = getattr(self, 'cover_path', None)
         if cpath is None:
             pf = open(os.path.join(dir, 'cover.jpg'), 'wb')
-            self.default_cover(pf)
-            cpath =  pf.name
+            if self.default_cover(pf):
+                cpath =  pf.name
         if cpath is not None and os.access(cpath, os.R_OK):
             opf.cover = cpath
             manifest.append(cpath)