Backport PR #12157: Properly declare the interactive framework for the qt4foo backends.

tacaswell · MeeseeksDev[bot] · commit 8ccd18b69abf · 2018-09-19T13:56:09.000Z
diff --git a/lib/matplotlib/backends/backend_qt4agg.py b/lib/matplotlib/backends/backend_qt4agg.py
@@ -8,4 +8,4 @@
 
 @_BackendQT5Agg.export
 class _BackendQT4Agg(_BackendQT5Agg):
-    pass
+    required_interactive_framework = "qt4"
diff --git a/lib/matplotlib/backends/backend_qt4cairo.py b/lib/matplotlib/backends/backend_qt4cairo.py
@@ -3,4 +3,4 @@
 
 @_BackendQT5Cairo.export
 class _BackendQT4Cairo(_BackendQT5Cairo):
-    pass
+    required_interactive_framework = "qt4"
