Update lib/matplotlib/testing/decorators.py

Co-authored-by: Greg Lucas <[email protected]>

Author: timhoffm

lib/matplotlib/testing/decorators.py

@@ -268,7 +268,7 @@ def wrapper(*args, extension, request, **kwargs):
                     'pdf': 'because Ghostscript is not installed',
                     'eps': 'because Ghostscript is not installed',
                     'svg': 'because Inkscape is not installed',
-                }.get(extension, '')
+                }.get(extension, 'on this system')
                 pytest.skip(f"Cannot compare {extension} files {reason}")
 
             img = _ImageComparisonBase(func, tol=tol, remove_text=remove_text,