Python shell debugger warning

[alexandra.zahradnikova@…]

The following bug report has been submitted:
Platform:        Linux-6.8.0-124-generic-x86_64-with-glibc2.35
ChimeraX Version: 1.12.dev202604290127 (2026-04-29 01:27:48 UTC)
Description
0.00s - Debugger warning: It seems that frozen modules are being used, which may 0.00s - make the debugger miss breakpoints. Please pass -Xfrozen_modules=off 0.00s - to python to disable frozen modules. 0.00s - Note: Debugging will proceed. Set PYDEVD_DISABLE_FILE_VALIDATION=1 to disable this validation. UCSF ChimeraX version: 1.12.dev202604290127 (2026-04-29) © 2016-2026 Regents of the University of California. All rights reserved.

Log:
> ui tool show Shell

0.00s - Debugger warning: It seems that frozen modules are being used, which
may  
0.00s - make the debugger miss breakpoints. Please pass -Xfrozen_modules=off  
0.00s - to python to disable frozen modules.  
0.00s - Note: Debugging will proceed. Set PYDEVD_DISABLE_FILE_VALIDATION=1 to
disable this validation.  
UCSF ChimeraX version: 1.12.dev202604290127 (2026-04-29)  
© 2016-2026 Regents of the University of California. All rights reserved.  
How to cite UCSF ChimeraX  




OpenGL version: 4.5 (Core Profile) Mesa 23.2.1-1ubuntu3.1~22.04.4
OpenGL renderer: llvmpipe (LLVM 15.0.7, 256 bits)
OpenGL vendor: Mesa

Python: 3.11.13
Locale: en_US.UTF-8
Qt version: PyQt6 6.10.2, Qt 6.10.0
Qt runtime version: 6.10.1
Qt platform: xcb

XDG_SESSION_TYPE=x11
DESKTOP_SESSION=ubuntu
XDG_SESSION_DESKTOP=
XDG_CURRENT_DESKTOP=ubuntu:GNOME
DISPLAY=:10.0
Manufacturer: Micro-Star International Co., Ltd.
Model: Desktop MPG Z890 Infinite X3 AI 2nd
OS: Ubuntu 22.04
Architecture: 64bit ELF
Virtual Machine: none
CPU: 20 Intel(R) Core(TM) Ultra 7 265KF
Cache Size: 30720 KB
Memory:
	               total        used        free      shared  buff/cache   available
	Mem:            62Gi        15Gi        33Gi       197Mi        14Gi        46Gi
	Swap:          2.0Gi          0B       2.0Gi

Graphics:
	02:00.0 VGA compatible controller [0300]: NVIDIA Corporation Device [10de:2c05] (rev a1)	
	Subsystem: Micro-Star International Co., Ltd. [MSI] Device [1462:5310]	
	Kernel modules: nvidiafb, nouveau

Installed Packages:
    accessible-pygments: 0.0.5
    aiohappyeyeballs: 2.6.1
    aiohttp: 3.13.1
    aiosignal: 1.4.0
    alabaster: 1.0.0
    annotated-types: 0.7.0
    anyio: 4.13.0
    appdirs: 1.4.4
    asttokens: 3.0.1
    attrs: 26.1.0
    babel: 2.18.0
    beautifulsoup4: 4.13.5
    blockdiag: 3.0.0
    blosc2: 4.1.2
    bs4: 0.0.2
    build: 1.3.0
    certifi: 2026.4.22
    cftime: 1.6.5
    charset-normalizer: 3.4.7
    ChimeraX-AddCharge: 1.5.20
    ChimeraX-AddH: 2.2.8
    ChimeraX-AlignmentAlgorithms: 2.0.2
    ChimeraX-AlignmentHdrs: 3.6.2
    ChimeraX-AlignmentMatrices: 2.1
    ChimeraX-Alignments: 3.2
    ChimeraX-AlphaFold: 1.0.1
    ChimeraX-AltlocExplorer: 1.2
    ChimeraX-AmberInfo: 1.0
    ChimeraX-Animations: 1.0
    ChimeraX-Aniso: 1.3.2
    ChimeraX-Arrays: 1.1
    ChimeraX-Atomic: 1.67.1
    ChimeraX-AtomicLibrary: 14.4
    ChimeraX-AtomSearch: 2.0.1
    ChimeraX-AxesPlanes: 2.4
    ChimeraX-BasicActions: 1.1.3
    ChimeraX-BILD: 1.0
    ChimeraX-BlastProtein: 3.0.0
    ChimeraX-Boltz: 1.1
    ChimeraX-BondRot: 2.0.4
    ChimeraX-BugReporter: 1.0.2
    ChimeraX-BuildStructure: 2.13.1
    ChimeraX-Bumps: 1.0
    ChimeraX-BundleBuilder: 1.6.0
    ChimeraX-ButtonPanel: 1.0.1
    ChimeraX-CageBuilder: 1.0.1
    ChimeraX-CellPack: 1.0
    ChimeraX-Centroids: 1.4.1
    ChimeraX-ChangeChains: 1.1
    ChimeraX-CheckWaters: 1.5
    ChimeraX-ChemGroup: 2.0.2
    ChimeraX-Clashes: 2.4
    ChimeraX-Cluster: 1.0
    ChimeraX-ColorActions: 1.0.5
    ChimeraX-ColorGlobe: 1.0
    ChimeraX-ColorKey: 1.5.8
    ChimeraX-CommandLine: 1.3.1
    ChimeraX-ConnectStructure: 2.0.1
    ChimeraX-Contacts: 1.0.1
    ChimeraX-Core: 1.12.dev202604290127
    ChimeraX-CoreFormats: 1.2
    ChimeraX-coulombic: 1.4.5
    ChimeraX-Crosslinks: 1.0
    ChimeraX-Crystal: 1.0
    ChimeraX-CrystalContacts: 1.0.1
    ChimeraX-DataFormats: 1.2.4
    ChimeraX-Dicom: 1.2.7
    ChimeraX-DistMonitor: 1.4.2
    ChimeraX-DockPrep: 1.2.1
    ChimeraX-Dssp: 2.0
    ChimeraX-EMDB-SFF: 1.0
    ChimeraX-ESMFold: 1.0
    ChimeraX-FileHistory: 1.0.1
    ChimeraX-FunctionKey: 1.0.1
    ChimeraX-Geometry: 1.3
    ChimeraX-gltf: 1.0
    ChimeraX-Graphics: 1.4.1
    ChimeraX-Hbonds: 2.5.3
    ChimeraX-Help: 1.3
    ChimeraX-HKCage: 1.3
    ChimeraX-IHM: 1.1
    ChimeraX-ImageFormats: 1.2
    ChimeraX-IMOD: 1.0
    ChimeraX-IO: 1.0.4
    ChimeraX-ItemsInspection: 1.0.1
    ChimeraX-IUPAC: 1.0
    ChimeraX-KVFinder: 1.8.2
    ChimeraX-Label: 1.4
    ChimeraX-LightingGUI: 1.0
    ChimeraX-LinuxSupport: 1.0.1
    ChimeraX-ListInfo: 1.3.1
    ChimeraX-Log: 1.2.2
    ChimeraX-LookingGlass: 1.1
    ChimeraX-Maestro: 1.9.2
    ChimeraX-Map: 1.3
    ChimeraX-MapData: 2.0
    ChimeraX-MapEraser: 1.0.1
    ChimeraX-MapFilter: 2.0.1
    ChimeraX-MapFit: 2.0
    ChimeraX-MapSeries: 2.1.1
    ChimeraX-Markers: 1.0.1
    ChimeraX-Mask: 1.0.2
    ChimeraX-MatchAlign: 1.1
    ChimeraX-MatchMaker: 2.4
    ChimeraX-MCopy: 1.0
    ChimeraX-MCPServer: 0.2.0
    ChimeraX-MDcrds: 2.19
    ChimeraX-MedicalToolbar: 1.1
    ChimeraX-Meeting: 1.0.1
    ChimeraX-Minimize: 1.3.8
    ChimeraX-MLP: 1.1.1
    ChimeraX-mmCIF: 2.16
    ChimeraX-MMTF: 2.2
    ChimeraX-ModelArchive: 1.0
    ChimeraX-Modeller: 1.5.23
    ChimeraX-ModelPanel: 1.6.1
    ChimeraX-ModelSeries: 1.0.1
    ChimeraX-Mol2: 2.0.3
    ChimeraX-Mole: 1.0
    ChimeraX-Morph: 1.0.2
    ChimeraX-MouseModes: 1.2
    ChimeraX-Movie: 1.0.1
    ChimeraX-MutationScores: 1.0
    ChimeraX-Neuron: 1.0
    ChimeraX-Nifti: 1.2
    ChimeraX-NMRSTAR: 1.0.2
    ChimeraX-NRRD: 1.2
    ChimeraX-Nucleotides: 2.0.3
    ChimeraX-OpenCommand: 1.15.4
    ChimeraX-OpenFold: 1.0
    ChimeraX-OrthoPick: 1.0.1
    ChimeraX-PDB: 2.7.13
    ChimeraX-PDBBio: 1.0.1
    ChimeraX-PDBLibrary: 1.0.5
    ChimeraX-PDBMatrices: 1.0
    ChimeraX-PickBlobs: 1.0.1
    ChimeraX-Positions: 1.0
    ChimeraX-PresetMgr: 1.1.4
    ChimeraX-ProfileGrids: 1.6
    ChimeraX-PubChem: 2.2
    ChimeraX-ReadPbonds: 1.0.1
    ChimeraX-Registration: 1.1.2
    ChimeraX-RemoteControl: 1.0
    ChimeraX-RenderByAttr: 1.8.2
    ChimeraX-RenumberResidues: 1.1
    ChimeraX-ResidueFit: 1.0.1
    ChimeraX-RestServer: 1.3.3
    ChimeraX-RNALayout: 1.0
    ChimeraX-RotamerLibMgr: 4.0
    ChimeraX-RotamerLibsDunbrack: 2.0
    ChimeraX-RotamerLibsDynameomics: 2.0
    ChimeraX-RotamerLibsRichardson: 2.0
    ChimeraX-SaveCommand: 1.5.2
    ChimeraX-Scenes: 0.3.1
    ChimeraX-SchemeMgr: 1.0
    ChimeraX-SDF: 2.0.3
    ChimeraX-Segger: 1.0
    ChimeraX-Segment: 1.0.1
    ChimeraX-Segmentations: 3.5.12
    ChimeraX-SelInspector: 1.0
    ChimeraX-SeqView: 2.18
    ChimeraX-Shape: 1.1
    ChimeraX-Shell: 1.0.1
    ChimeraX-Shortcuts: 1.2.1
    ChimeraX-ShowSequences: 1.0.3
    ChimeraX-SideView: 1.0.1
    ChimeraX-SimilarStructures: 1.0.1
    ChimeraX-Smiles: 2.1.2
    ChimeraX-SmoothLines: 1.0
    ChimeraX-SNFG: 1.0
    ChimeraX-SpaceNavigator: 1.0
    ChimeraX-StdCommands: 1.19.3
    ChimeraX-STL: 1.0.1
    ChimeraX-Storm: 1.0
    ChimeraX-StructMeasure: 1.2.1
    ChimeraX-Struts: 1.0.1
    ChimeraX-Surface: 1.0.1
    ChimeraX-SwapAA: 2.0.1
    ChimeraX-SwapRes: 2.5.3
    ChimeraX-TapeMeasure: 1.0
    ChimeraX-TaskManager: 1.0
    ChimeraX-Test: 1.0
    ChimeraX-Toolbar: 1.2.4
    ChimeraX-ToolshedUtils: 1.2.4
    ChimeraX-Topography: 1.0
    ChimeraX-ToQuest: 1.0
    ChimeraX-Tug: 1.0.1
    ChimeraX-UI: 1.50.5
    ChimeraX-Umap: 1.0
    ChimeraX-uniprot: 2.3.2
    ChimeraX-UnitCell: 1.0.1
    ChimeraX-ViewDock: 1.6.1
    ChimeraX-VIPERdb: 1.0
    ChimeraX-Vive: 1.1
    ChimeraX-VolumeMenu: 1.0.1
    ChimeraX-vrml: 1.0
    ChimeraX-VTK: 1.0
    ChimeraX-WavefrontOBJ: 1.0
    ChimeraX-WebCam: 1.0.2
    ChimeraX-WebServices: 1.1.5
    ChimeraX-Zone: 1.0.1
    click: 8.3.3
    colorama: 0.4.6
    comm: 0.2.3
    contourpy: 1.3.3
    coverage: 7.13.5
    cxservices: 1.2.3
    cycler: 0.12.1
    Cython: 3.2.4
    DateTime: 6.0
    debugpy: 1.8.20
    decorator: 5.2.1
    distro: 1.9.0
    docutils: 0.21.2
    et_xmlfile: 2.0.0
    executing: 2.2.1
    filelock: 3.19.1
    fonttools: 4.62.1
    frozenlist: 1.8.0
    funcparserlib: 2.0.0a0
    glfw: 2.10.0
    grako: 3.16.5
    h11: 0.16.0
    h5py: 3.16.0
    html2text: 2025.4.15
    httpcore: 1.0.9
    httpx: 0.28.1
    httpx-sse: 0.4.3
    idna: 3.13
    ihm: 2.2
    imagecodecs: 2024.6.1
    imagesize: 2.0.0
    iniconfig: 2.3.0
    ipykernel: 7.1.0
    ipython: 9.9.0
    ipython_pygments_lexers: 1.1.1
    jedi: 0.19.2
    Jinja2: 3.1.6
    jsonschema: 4.26.0
    jsonschema-specifications: 2025.9.1
    jupyter_client: 8.8.0
    jupyter_core: 5.9.1
    kiwisolver: 1.5.0
    line_profiler: 5.0.0
    lxml: 6.0.2
    lz4: 4.3.2
    Markdown: 3.8.2
    MarkupSafe: 3.0.3
    matplotlib: 3.10.7
    matplotlib-inline: 0.2.1
    mcp: 1.18.0
    msgpack: 1.1.1
    multidict: 6.7.1
    narwhals: 2.20.0
    ndindex: 1.10.1
    nest-asyncio: 1.6.0
    netCDF4: 1.6.5
    networkx: 3.3
    nibabel: 5.2.0
    nptyping: 2.5.0
    numexpr: 2.14.1
    numpy: 1.26.4
    nvidia-nvjitlink-cu12: 12.9.86
    OpenMM: 8.4.0
    OpenMM-CUDA-12: 8.4.0
    openpyxl: 3.1.5
    openvr: 1.26.701
    packaging: 25.0
    pandas: 3.0.2
    ParmEd: 4.2.2
    parso: 0.8.6
    pathlib: 1.0.1
    pep517: 0.13.1
    pexpect: 4.9.0
    pickleshare: 0.7.5
    pillow: 11.3.0
    pip: 25.2
    pkginfo: 1.12.1.2
    platformdirs: 4.9.6
    plotly: 6.7.0
    pluggy: 1.6.0
    prompt_toolkit: 3.0.52
    propcache: 0.4.1
    psutil: 7.0.0
    ptyprocess: 0.7.0
    pure_eval: 0.2.3
    py-cpuinfo: 9.0.0
    pybind11: 3.0.1
    pycollada: 0.8
    pydantic: 2.13.3
    pydantic-settings: 2.14.0
    pydantic_core: 2.46.3
    pydata-sphinx-theme: 0.17.1
    pydicom: 2.4.4
    Pygments: 2.18.0
    pynmrstar: 3.5.1
    pynrrd: 1.0.0
    PyOpenGL: 3.1.10
    PyOpenGL-accelerate: 3.1.10
    pyopenxr: 1.1.4501
    pyparsing: 3.3.2
    pyproject_hooks: 1.2.0
    PyQt6: 6.10.2
    PyQt6-Qt6: 6.10.1
    PyQt6-WebEngine: 6.10.0
    PyQt6-WebEngine-Qt6: 6.10.1
    PyQt6_sip: 13.10.3
    pytest: 9.0.3
    pytest-cov: 7.1.0
    python-dateutil: 2.9.0.post0
    python-dotenv: 1.2.2
    python-multipart: 0.0.27
    pytz: 2026.1.post1
    pyzmq: 27.1.0
    qtconsole: 5.7.0
    QtPy: 2.4.3
    qtshim: 1.2.2
    RandomWords: 0.4.0
    referencing: 0.37.0
    requests: 2.32.5
    roman-numerals: 4.1.0
    rpds-py: 0.30.0
    scipy: 1.14.0
    setuptools: 80.9.0
    sfftk-rw: 0.8.1
    six: 1.17.0
    snowballstemmer: 3.0.1
    sortedcontainers: 2.4.0
    soupsieve: 2.8.3
    Sphinx: 9.0.4
    sphinx-autodoc-typehints: 3.6.1
    sphinxcontrib-applehelp: 2.0.0
    sphinxcontrib-blockdiag: 3.0.0
    sphinxcontrib-devhelp: 2.0.0
    sphinxcontrib-htmlhelp: 2.1.0
    sphinxcontrib-jsmath: 1.0.1
    sphinxcontrib-qthelp: 2.0.0
    sphinxcontrib-serializinghtml: 2.0.0
    sse-starlette: 3.4.1
    stack-data: 0.6.3
    starlette: 1.0.0
    superqt: 0.7.6
    tables: 3.10.2
    tcia_utils: 3.2.1
    tifffile: 2025.3.13
    tinyarray: 1.2.5
    tornado: 6.5.5
    tqdm: 4.67.3
    traitlets: 5.14.3
    typing-inspection: 0.4.2
    typing_extensions: 4.15.0
    Unidecode: 1.4.0
    urllib3: 2.6.3
    uvicorn: 0.46.0
    wcwidth: 0.6.0
    webcolors: 24.11.1
    wheel: 0.45.1
    wheel-filename: 1.4.2
    yarl: 1.23.0
    zope.interface: 8.4

[Tom Goddard]

I'm not sure what ChimeraX problem you are reporting. The ChimeraX log in your report shows a warning message after starting the Python shell within ChimeraX. That is normal and is just advisory. It means that some Python system modules are built-in to the Python executable instead of loaded from .pyc files. That can make debugging not able to inspect the code for those modules. But it also makes Python start much faster. When debugging you are probably interested in debugging the ChimeraX modules which are not frozen, so I don't think this limitation will affect you.

[alexandra.zahradnikova@…]

Hi
I have sent it because I did not know what it means. It does not make any problems.
Thank you for the information.
Best regards
sasha

-----Original Message-----
From: ChimeraX [mailto:ChimeraX-bugs-admin@cgl.ucsf.edu] 
Sent: Wednesday, July 22, 2026 20:10
To: alexandra.zahradnikova@savba.sk; goddard@cgl.ucsf.edu
Subject: Re: [ChimeraX] #20782: Python shell debugger warning (was: ChimeraX bug report submission)

#20782: Python shell debugger warning
-----------------------------------------------+-------------------------
          Reporter:  alexandra.zahradnikova@…  |      Owner:  Tom Goddard
              Type:  defect                    |     Status:  assigned
          Priority:  normal                    |  Milestone:
         Component:  Core                      |    Version:
        Resolution:                            |   Keywords:
        Blocked By:                            |   Blocking:
Notify when closed:                            |   Platform:  all
           Project:  ChimeraX                  |
-----------------------------------------------+-------------------------
Changes (by Tom Goddard):

 * component:  Unassigned => Core
 * owner:  (none) => Tom Goddard
 * platform:   => all
 * project:   => ChimeraX
 * status:  new => assigned
 * summary:  ChimeraX bug report submission => Python shell debugger warning

Comment:

 I'm not sure what ChimeraX problem you are reporting.  The ChimeraX log in
 your report shows a warning message after starting the Python shell within
 ChimeraX.  That is normal and is just advisory.  It means that some Python
 system modules are built-in to the Python executable instead of loaded
 from .pyc files.  That can make debugging not able to inspect the code for
 those modules.  But it also makes Python start much faster.  When
 debugging you are probably interested in debugging the ChimeraX modules
 which are not frozen, so I don't think this limitation will affect you.

[Tom Goddard]

I agree the warning about frozen modules when starting the shell on Linux is confusing. Since few people are running a debugger I think the warning does more harm than good, so I suppressed the warning in tomorrow's daily build.

Thanks for reporting the problem.