Improve skip message for image comparison tests

timhoffm · timhoffm · commit 8c951885e7f6 · 2022-09-08T21:45:53.000+02:00
diff --git a/lib/matplotlib/testing/decorators.py b/lib/matplotlib/testing/decorators.py
@@ -264,7 +264,12 @@ def wrapper(*args, extension, request, **kwargs):
                 kwargs['request'] = request
 
             if extension not in comparable_formats():
-                pytest.skip(f"Cannot compare {extension} files on this system")
+                reason = {
+                    'pdf': 'because Ghostscript is not installed',
+                    'eps': 'because Ghostscript is not installed',
+                    'svg': 'because Inkscape is not installed',
+                }.get(extension, '')
+                pytest.skip(f"Cannot compare {extension} files {reason}")
 
             img = _ImageComparisonBase(func, tol=tol, remove_text=remove_text,
                                        savefig_kwargs=savefig_kwargs)
