Backport PR #22596: Fix backend in matplotlibrc if unset in mplsetup.cfg

greglucas · meeseeksmachine · commit ea16e1788b1c · 2022-03-04T14:43:09.000Z
diff --git a/setup.py b/setup.py
@@ -214,7 +214,7 @@ def update_matplotlibrc(path):
     template_lines[backend_line_idx] = (
         "#backend: {}\n".format(setupext.options["backend"])
         if setupext.options["backend"]
-        else "##backend: Agg")
+        else "##backend: Agg\n")
     path.write_text("".join(template_lines))
 
 
