From 3c451847b852a09fdaac3b6d0902acbfd347f0df Mon Sep 17 00:00:00 2001
From: Tim Hoffmann <2836374+timhoffm@users.noreply.github.com>
Date: Tue, 23 Apr 2019 15:22:29 +0200
Subject: [PATCH] Better ImportError message when trying to use Gtk3Agg backend
 without cairo

---
 lib/matplotlib/backends/backend_gtk3agg.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/matplotlib/backends/backend_gtk3agg.py b/lib/matplotlib/backends/backend_gtk3agg.py
index 8e5b991daf80..64008b0b0eab 100644
--- a/lib/matplotlib/backends/backend_gtk3agg.py
+++ b/lib/matplotlib/backends/backend_gtk3agg.py
@@ -1,7 +1,11 @@
 import numpy as np
 
 from .. import cbook
-from . import backend_agg, backend_cairo, backend_gtk3
+try:
+    from . import backend_cairo
+except ImportError as e:
+    raise ImportError('backend Gtk3Agg requires cairo') from e
+from . import backend_agg, backend_gtk3
 from .backend_cairo import cairo
 from .backend_gtk3 import Gtk, _BackendGTK3
 from matplotlib import transforms