Bug#918993: sagemath-jupyter: Invalid path to sage kernel makes notebook unusable

[Amaury Pouly]

Package: sagemath-jupyter
Version: 8.4-4
Severity: important

Dear Maintainer,

the jupyter notebook with sage is unusable because the kernel config is invalid,
in /usr/share/jupyter/kernels/sagemath/kernel.json there is:

{"display_name": "SageMath 8.6.rc0", 
 "argv": ["/build/sagemath-FTVAsu/sagemath-8.6~rc0/debian/build/usr/bin/sage",
  "--python", "-m", "sage.repl.ipython_kernel", "-f", "{connection_file}"]}

The hardcoded path contains what looks like a temporary build path, which
does not exists on my system. This makes the sage kernel unusable with jupyuter.
I tried to manually replace the path with /usr/bin/sage and it works.

-- System Information:
Debian Release: buster/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.19.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8), LANGUAGE=fr (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages sagemath-jupyter depends on:
ii  jupyter-client                          5.2.3-1
ii  jupyter-core                            4.4.0-2
ii  jupyter-nbextension-jupyter-js-widgets  6.0.0-2
ii  python-ipykernel                        4.9.0-1
ii  python-ipywidgets                       6.0.0-2
ii  python-nbconvert                        5.4-1
ii  python-nbformat                         4.4.0-1
ii  python-notebook                         5.4.1-1
ii  sagemath                                8.4-4

sagemath-jupyter recommends no packages.

sagemath-jupyter suggests no packages.

-- no debconf information