Jupyter subcommands broken

[bnavigator]

So I have accepted and forwarded @schubi2's submit requests in d:l:p:jupyter. It broke a lot of packages down the tree.

With notebook still on u-a

$ ls -l /usr/bin/jupyter
lrwxrwxrwx 1 root root 4 25. Okt 16:46 /usr/bin/jupyter -> alts
$ ls -l /usr/bin/jupyter-notebook
lrwxrwxrwx 1 root root 34 22. Okt 00:00 /usr/bin/jupyter-notebook -> /etc/alternatives/jupyter-notebook
$ jupyter-notebook list
Currently running servers:
$ jupyter notebook list
Currently running servers:
$ 

With alts:

$ ls -l /usr/bin/jupyter
lrwxrwxrwx 1 root root 4 Oct 27 00:02 /usr/bin/jupyter -> alts
$ ls -l /usr/bin/jupyter-notebook
lrwxrwxrwx 1 root root 4 Oct 27 11:55 /usr/bin/jupyter-notebook -> alts
$ jupyter-notebook list
Currently running servers:
$ jupyter notebook list
$ 

no output here!
The command is not called at all, jupyter notebook should start a notebook server and launch a browser, but does nothing.

Looks like libalternatives can not handle the nested calling of subcommands.

I am going to revert all packages in d:l:p:jupyter. Please resubmit when you have a working and tested solution.

[bnavigator]

Some debugging info:

[ben@skylab:~]% python3 -m pdb /usr/bin/jupyter-3.8 trust-3.8 --help                                                                                                                 [0]
> /usr/bin/jupyter-3.8(3)<module>()
-> import re
(Pdb) b os.py:591
Breakpoint 1 at /usr/lib64/python3.8/os.py:591
(Pdb) c
> /usr/lib64/python3.8/os.py(591)_execvpe()
-> exec_func(file, *argrest)
(Pdb) p exec_func, file, argrest
(<built-in function execv>, '/usr/bin/jupyter-trust-3.8', (['trust-3.8', '--help'],))
(Pdb) c
Sign one or more Jupyter notebooks with your key, to trust their dynamic (HTML,
Javascript) output.

Otherwise, you will have to re-execute the notebook to see output.

Options
-------

Arguments that take values are actually convenience aliases to full
Configurables, whose aliases are listed on the help line. For more information
on full configurables, see '--help-all'.

--reset
    Delete the trusted notebook cache.
    All previously signed notebooks will become untrusted.
--debug
    set log level to logging.DEBUG (maximize logging output)
--generate-config
    generate default config file
-y
    Answer yes to any questions instead of prompting.
--log-level=<Enum> (Application.log_level)
    Default: 30
    Choices: (0, 10, 20, 30, 40, 50, 'DEBUG', 'INFO', 'WARN', 'ERROR', 'CRITICAL')
    Set the log level by value or name.
--config=<Unicode> (JupyterApp.config_file)
    Default: ''
    Full path of a config file.

To see all available configurables, use `--help-all`

Examples
--------

    jupyter trust mynotebook.ipynb and_this_one.ipynb

[ben@skylab:~]% python3 -m pdb /usr/bin/jupyter-3.8 trust --help                                                                                                                     [0]
> /usr/bin/jupyter-3.8(3)<module>()
-> import re
(Pdb) b os.py:591
Breakpoint 1 at /usr/lib64/python3.8/os.py:591
(Pdb) c
> /usr/lib64/python3.8/os.py(591)_execvpe()
-> exec_func(file, *argrest)
(Pdb) p exec_func, file, argrest
(<built-in function execv>, '/usr/bin/jupyter-trust', (['trust', '--help'],))
(Pdb) c
[ben@skylab:~]%                                                                                                                                                                    [255]

Note the error code 255 in the end after calling execv()

[schubi2]

It seems not to be the "argv0" problem:
See https://build.opensuse.org/request/show/927749

[bnavigator]

It is an argv0 problem, just in a different way than #7. When alts is called, with argv[0]='notebook', it does not know that this is meant to be 'jupyter-notebook' and does not even read the correct config file.

[AdamMajer]

Correct. If argv0 is /path/something, it will then go via /usr/share/libalternatives/something/` data. If argv0 != binary_name, then there is really no way to know how the program was executed and so then this can't really work anymore.

[bnavigator]

IMHO this has to be documented very excplicitly. You can only convert a package to using libalternatives, when you can guarantee that nothing calls the executable with argv[0] != binary_name. Something you actually can never guarantee.

[bnavigator]

Closed by jupyter/jupyter_core#248 and sr#931172