Tk graphics backend is giving error on Big Sur with DMG installer

Changed ‘Graphics backend’ (Graphics tab) to ‘tkinter’ and back to ‘inline’ On MacOS Big Sur Python 3

Traceback

  File "/Applications/Spyder.app/Contents/Resources/lib/python3.9/spyder/preferences/configdialog.py", line 236, in button_clicked
    configpage.apply_changes()
  File "/Applications/Spyder.app/Contents/Resources/lib/python3.9/spyder/preferences/configdialog.py", line 99, in apply_changes
    self.apply_callback()
  File "/Applications/Spyder.app/Contents/Resources/lib/python3.9/spyder/preferences/configdialog.py", line 282, in <lambda>
    self.apply_settings(self.changed_options))
  File "/Applications/Spyder.app/Contents/Resources/lib/python3.9/spyder/plugins/ipythonconsole/plugin.py", line 369, in apply_plugin_settings
    client_backend_not_inline = [
  File "/Applications/Spyder.app/Contents/Resources/lib/python3.9/spyder/plugins/ipythonconsole/plugin.py", line 370, in <listcomp>
    client.shellwidget.get_matplotlib_backend() != inline_backend
  File "/Applications/Spyder.app/Contents/Resources/lib/python3.9/spyder/plugins/ipythonconsole/widgets/shell.py", line 341, in get_matplotlib_backend
    return self.call_kernel(
  File "/Applications/Spyder.app/Contents/Resources/lib/python3.9/spyder_kernels/comms/commbase.py", line 550, in __call__
    raise CommError("The comm is not connected.")
spyder_kernels.comms.commbase.CommError: The comm is not connected.
WARNING:traitlets:kernel died: 25.001062870025635
WARNING:traitlets:kernel died: 25.00008487701416
WARNING:traitlets:kernel died: 25.003293991088867
WARNING:traitlets:kernel died: 25.00503396987915

Versions

• Spyder version: 4.2.1
• Python version: 3.9.1
• Qt version: 5.12.10
• PyQt5 version: 5.12.3
• Operating System: Darwin 20.2.0

Dependencies

# Mandatory:
applaunchservices >=0.1.7       :  0.2.1 (OK)
atomicwrites >=1.2.0            :  1.4.0 (OK)
chardet >=2.0.0                 :  4.0.0 (OK)
cloudpickle >=0.5.0             :  1.6.0 (OK)
diff_match_patch >=20181111     :  20200713 (OK)
intervaltree >=3.0.2            :  3.1.0 (OK)
IPython >=7.6.0                 :  7.19.0 (OK)
jedi =0.17.2                    :  0.17.2 (OK)
jsonschema >=3.2.0              :  3.2.0 (OK)
keyring >=17.0.0                :  21.5.0 (OK)
nbconvert >=4.0                 :  6.0.7 (OK)
numpydoc >=0.6.0                :  1.1.0 (OK)
parso =0.7.0                    :  0.7.0 (OK)
pexpect >=4.4.0                 :  4.8.0 (OK)
pickleshare >=0.4               :  0.7.5 (OK)
psutil >=5.3                    :  5.7.3 (OK)
pygments >=2.0                  :  2.7.3 (OK)
pylint >=1.0                    :  2.6.0 (OK)
pyls >=0.36.2;<1.0.0            :  0.36.2 (OK)
pyls_black >=0.4.6              :  0.4.6 (OK)
pyls_spyder >=0.3.0             :  0.3.0 (OK)
qdarkstyle >=2.8                :  2.8.1 (OK)
qtawesome >=0.5.7               :  1.0.2 (OK)
qtconsole >=5.0.1               :  5.0.1 (OK)
qtpy >=1.5.0                    :  1.9.0 (OK)
setuptools >=39.0.0             :  51.0.0 (OK)
sphinx >=0.6.6                  :  3.3.1 (OK)
spyder_kernels >=1.10.1;<1.11.0 :  1.10.1 (OK)
textdistance >=4.2.0            :  4.2.0 (OK)
three_merge >=0.1.1             :  0.1.1 (OK)
watchdog >=0.10.3               :  1.0.2 (OK)
zmq >=17                        :  20.0.0 (OK)

# Optional:
cython >=0.21                   :  0.29.21 (OK)
matplotlib >=2.0.0              :  3.3.3 (OK)
numpy >=1.7                     :  1.19.4 (OK)
pandas >=1.1.1                  :  None (NOK)
scipy >=0.17.0                  :  1.5.4 (OK)
sympy >=0.7.3                   :  1.7.1 (OK)

[mrclary]

Okay, after all that, it seems that this issue is already resolved.

• I’ve checked that the latest artifact from #14667 does have Tcl/Tck versions 8.6 and this issue does not manifest on Big Sur.
• I’ve checked that our latest release 4.2.1 was built with Tcl/Tck versions 8.5 and this issue does manifest on Big Sur.

So, I conclude that some time recently Homebrew updated their Python build to use Tcl/Tck versions 8.6 and macos-latest GitHub action also subsequently updated its image and no action is required on our part.

[ccordoba12]

That’s great news! Thanks @mrclary for digging into this issue and finding a solution for it!