Matplotlib backend not specified by default in Windows machines [Python: Julia: UndefVarError: Core not defined in PythonCall.Compat] #676
Description
I just updated PythonCall.jl to v0.9.28 and Julia to v1.11.7 on my Window 11 machine. With the previous versions, i.e., v0.9.27 and v1.11.6, respectively, I didn't have to set up the backend of matplotlib.pyplot explicitly. However, with the current new versions, the backend is not specified by default, and got the following error. I don't have any problems on my iMac. Only under Windows, I encountered this problem. What's wrong here?
julia> using PythonCall
julia> plt=pyimport("matplotlib.pyplot")
Python: <module 'matplotlib.pyplot' from 'C:\\Users\\xxx\\.julia\\environments\\v1.11\\.CondaPkg\\.pixi\\envs\\default\\Lib\\site-packages\\matplotlib\\pyplot.py'>
julia> plt.get_backend()
ERROR: Python: Julia: UndefVarError: `Core` not defined in `PythonCall.Compat`
Hint: It looks like two or more modules export different bindings with this name, resulting in ambiguity. Try explicitly importing it from a particular module, or qualifying the name with the module it should come from.
Hint: a global variable of this name also exists in Core.
Stacktrace:
[1] (::PythonCall.Compat.var"#1#2")()
@ PythonCall.Compat C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\Compat\gui.jl:162
[2] pyjlany_call(self::PythonCall.Compat.var"#1#2", args_::Py, kwargs_::Py)
@ PythonCall.JlWrap C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\JlWrap\any.jl:49
[3] _pyjl_callmethod(f::Any, self_::Ptr{PythonCall.C.PyObject}, args_::Ptr{PythonCall.C.PyObject}, nargs::Int64)
@ PythonCall.JlWrap C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\JlWrap\base.jl:71
[4] _pyjl_callmethod(o::Ptr{PythonCall.C.PyObject}, args::Ptr{PythonCall.C.PyObject})
@ PythonCall.JlWrap.Cjl C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\JlWrap\C.jl:63
[5] PyObject_CallObject
@ C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\C\pointers.jl:300 [inlined]
[6] macro expansion
@ C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\Core\Py.jl:118 [inlined]
[7] pycallargs(f::Py)
@ PythonCall.Core C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\Core\builtins.jl:193
[8] #pycall#21
@ C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\Core\builtins.jl:217 [inlined]
[9] pycall
@ C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\Core\builtins.jl:203 [inlined]
[10] (::Py)()
@ PythonCall.Core C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\Core\Py.jl:334
[11] top-level scope
@ REPL[3]:1
[12] eval
@ .\boot.jl:430 [inlined]
[13] eval
@ .\Base.jl:130 [inlined]
[14] repleval(m::Module, code::Expr, ::String)
@ VSCodeServer c:\Users\xxx\.vscode\extensions\julialang.language-julia-1.149.2\scripts\packages\VSCodeServer\src\repl.jl:229
[15] #112
@ c:\Users\xxx\.vscode\extensions\julialang.language-julia-1.149.2\scripts\packages\VSCodeServer\src\repl.jl:192 [inlined]
[16] with_logstate(f::VSCodeServer.var"#112#114"{…}, logstate::Base.CoreLogging.LogState)
@ Base.CoreLogging .\logging\logging.jl:524
[17] with_logger
@ .\logging\logging.jl:635 [inlined]
[18] (::VSCodeServer.var"#111#113"{Module, Expr, REPL.LineEditREPL, REPL.LineEdit.Prompt})()
@ VSCodeServer c:\Users\xxx\.vscode\extensions\julialang.language-julia-1.149.2\scripts\packages\VSCodeServer\src\repl.jl:193
[19] #invokelatest#2
@ .\essentials.jl:1055 [inlined]
[20] invokelatest(::Any)
@ Base .\essentials.jl:1052
[21] (::VSCodeServer.var"#64#65")()
@ VSCodeServer c:\Users\xxx\.vscode\extensions\julialang.language-julia-1.149.2\scripts\packages\VSCodeServer\src\eval.jl:34
Python stacktrace:
[1] __call__
@ C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\JlWrap\any.jl:262
[2] find_module
@ <string>:9
[3] _find_spec_legacy
@ <frozen importlib._bootstrap>:1050
[4] _find_spec
@ <frozen importlib._bootstrap>:1076
[5] _find_and_load_unlocked
@ <frozen importlib._bootstrap>:1140
[6] _find_and_load
@ <frozen importlib._bootstrap>:1178
[7] _setup_pyqt5plus
@ C:\Users\xxx\.julia\environments\v1.11\.CondaPkg\.pixi\envs\default\Lib\site-packages\matplotlib\backends\qt_compat.py:79
[8] <module>
@ C:\Users\xxx\.julia\environments\v1.11\.CondaPkg\.pixi\envs\default\Lib\site-packages\matplotlib\backends\qt_compat.py:125
[9] <module>
@ C:\Users\xxx\.julia\environments\v1.11\.CondaPkg\.pixi\envs\default\Lib\site-packages\matplotlib\backends\backend_qtagg.py:9
[10] _call_with_frames_removed
@ <frozen importlib._bootstrap>:241
[11] exec_module
@ <frozen importlib._bootstrap_external>:940
[12] _load_unlocked
@ <frozen importlib._bootstrap>:690
[13] _find_and_load_unlocked
@ <frozen importlib._bootstrap>:1149
[14] _find_and_load
@ <frozen importlib._bootstrap>:1178
[15] _gcd_import
@ <frozen importlib._bootstrap>:1206
[16] import_module
@ importlib C:\Users\xxx\.julia\environments\v1.11\.CondaPkg\.pixi\envs\default\Lib\importlib\__init__.py:126
[17] load_backend_module
@ matplotlib.backends.registry C:\Users\xxx\.julia\environments\v1.11\.CondaPkg\.pixi\envs\default\Lib\site-packages\matplotlib\backends\registry.py:323
[18] switch_backend
@ matplotlib.pyplot C:\Users\xxx\.julia\environments\v1.11\.CondaPkg\.pixi\envs\default\Lib\site-packages\matplotlib\pyplot.py:415
[19] switch_backend
@ matplotlib.pyplot C:\Users\xxx\.julia\environments\v1.11\.CondaPkg\.pixi\envs\default\Lib\site-packages\matplotlib\pyplot.py:400
[20] __getitem__
@ matplotlib C:\Users\xxx\.julia\environments\v1.11\.CondaPkg\.pixi\envs\default\Lib\site-packages\matplotlib\__init__.py:764
[21] get_backend
@ matplotlib C:\Users\xxx\.julia\environments\v1.11\.CondaPkg\.pixi\envs\default\Lib\site-packages\matplotlib\__init__.py:1281
Stacktrace:
[1] pythrow()
@ PythonCall.Core C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\Core\err.jl:77
[2] errcheck
@ C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\Core\err.jl:10 [inlined]
[3] pycallargs(f::Py)
@ PythonCall.Core C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\Core\builtins.jl:193
[4] #pycall#21
@ C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\Core\builtins.jl:217 [inlined]
[5] pycall
@ C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\Core\builtins.jl:203 [inlined]
[6] (::Py)()
@ PythonCall.Core C:\Users\xxx\.julia\packages\PythonCall\mkWc2\src\Core\Py.jl:334
[7] top-level scope
@ REPL[3]:1
Some type information was truncated. Use `show(err)` to see complete types.