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Launcher crashes when kernel is removed #5676

fcollonval opened this issue Nov 26, 2018 · 1 comment

Launcher crashes when kernel is removed #5676

fcollonval opened this issue Nov 26, 2018 · 1 comment


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@fcollonval fcollonval commented Nov 26, 2018

Describe the bug

When using nb_conda_kernels, removing an existing environment and opening the launcher results in an empty blank launcher.

To Reproduce
Steps to reproduce the behavior:

  1. Install nb_conda_kernels (available on conda-forge)
  2. Be sure to have multiple conda environment
    Dummy environment can be created through conda create -n dummy ipykernel
  3. Launch JupyterLab
  4. Open a notebook
  5. Remove one of the conda environment (conda env remove -n dummy)
  6. Open the launcher

Expected behavior
The launcher should appears with all environments minus the deleted one.


  • OS: Windows 7 64bits
  • Browser chrome 61.0
  • JupyterLab 0.35.3

Additional context

Browser Output
index.js:380 TypeError: Cannot read property 'display_name' of undefined
    at label (http://localhost:8888/lab/static/vendors~main.9eb87bab456c37d46462.js:285100:73)
    at CommandRegistry.push.5TpB.CommandRegistry.label (http://localhost:8888/lab/static/vendors~main.9eb87bab456c37d46462.js:29210:32)
    at Object.sortCmp (http://localhost:8888/lab/static/vendors~main.9eb87bab456c37d46462.js:33054:33)
    at categories.(anonymous function).categories.(anonymous function).sort (http://localhost:8888/lab/static/vendors~main.9eb87bab456c37d46462.js:32926:32)
    at Array.sort (native)
    at Launcher.render (http://localhost:8888/lab/static/vendors~main.9eb87bab456c37d46462.js:32925:47)
    at Launcher.onUpdateRequest (http://localhost:8888/lab/static/vendors~main.9eb87bab456c37d46462.js:295544:26)
    at Launcher.push.FmDU.Widget.processMessage (http://localhost:8888/lab/static/vendors~main.9eb87bab456c37d46462.js:248745:22)
    at invokeHandler (http://localhost:8888/lab/static/vendors~main.9eb87bab456c37d46462.js:393572:21)
    at sendMessage (http://localhost:8888/lab/static/vendors~main.9eb87bab456c37d46462.js:393308:13)

Associated bug
Creating new environments does not lead in additional cards in the launcher.

Possible fix
Session.specsChanged signal could use to listen for kernel changes.

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@jasongrout jasongrout commented Jan 24, 2019

Next step is to determine if this is nb_conda_kernel's fault, or JLab's fault.

@lock lock bot locked as resolved and limited conversation to collaborators Aug 8, 2019
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5 participants