From 4ae3a55b7bab98697ec9561469f2d7b27a5eefbc Mon Sep 17 00:00:00 2001
From: Alan <>
Date: Mon, 19 Jan 2026 18:57:05 +1100
Subject: [PATCH 1/3] Fix: missing 1 required positional argument: 'canvas' in
 Toolbar init

https://github.com/matplotlib/ipympl/issues/488
---
 ipympl/backend_nbagg.py | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/ipympl/backend_nbagg.py b/ipympl/backend_nbagg.py
index a6bb904b..3ccb1c7e 100644
--- a/ipympl/backend_nbagg.py
+++ b/ipympl/backend_nbagg.py
@@ -122,10 +122,8 @@ class Toolbar(DOMWidget, NavigationToolbar2WebAgg):
 
     _current_action = Enum(values=['pan', 'zoom', ''], default_value='').tag(sync=True)
 
-    def __init__(self, canvas, *args, **kwargs):
-        DOMWidget.__init__(self, *args, **kwargs)
-        NavigationToolbar2WebAgg.__init__(self, canvas, *args, **kwargs)
-
+    def __init__(self, canvas, **kwargs):
+        super().__init__(canvas=canvas, **kwargs)
         self.on_msg(self.canvas._handle_message)
 
     def export(self):

From b57a3311dc85a9c03d9b005526ad2c6d8d33e2f9 Mon Sep 17 00:00:00 2001
From: Alan <>
Date: Tue, 20 Jan 2026 14:27:19 +1100
Subject: [PATCH 2/3] Use super pattern in Canvas__init__ for better
 consistency.

---
 ipympl/backend_nbagg.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/ipympl/backend_nbagg.py b/ipympl/backend_nbagg.py
index 3ccb1c7e..12c28c5a 100644
--- a/ipympl/backend_nbagg.py
+++ b/ipympl/backend_nbagg.py
@@ -238,9 +238,8 @@ class Canvas(DOMWidget, FigureCanvasWebAggCore):
     # Static as it should be the same for all canvases
     current_dpi_ratio = 1.0
 
-    def __init__(self, figure, *args, **kwargs):
-        DOMWidget.__init__(self, *args, **kwargs)
-        FigureCanvasWebAggCore.__init__(self, figure, *args, **kwargs)
+    def __init__(self, figure, **kwargs):
+        super().__init__(figure=figure, **kwargs)
 
         self.on_msg(self._handle_message)
 

From 3e920f2e55ccea06f0821a96ad93b3d8b96632aa Mon Sep 17 00:00:00 2001
From: Alan <>
Date: Tue, 20 Jan 2026 14:28:24 +1100
Subject: [PATCH 3/3] DEMO fixed with jupyter-widgets/ipywidgets#4002

---
 .github/workflows/main.yml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 519c2dff..d9557b90 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -104,6 +104,9 @@ jobs:
       - name: Validate the labextension
         run: jupyter labextension list 2>&1 | grep jupyter-matplotlib
 
+      - name: Install ipywidgets patched version (temporary)
+        run: pip install --force-reinstall https://github.com/fleming79/ipylab/releases/download/v2.0.9/ipywidgets-8.1.8-py3-none-any.whl
+
       - name: Run pytest
         run: pytest -v .