Resolve issue #8

[trybik]

Closes #8

Changes incl:

• use old versions to make repo2docker install jupyterlab/latex extension (I've tried w/ no success also 1.x and 2.x for Python packages)
• default to XeTeX and include missing image for jupyterlab/latex preview to work (manually tested)
• minor cleanups in conda env file: specify explicitly python/pip/setuptools + use pip for installation of pypi packages

[choldgraf]

Hey - thanks for the PR! I don't think that we want the solution to be downgrading jupyterlab to < 1.0...that's a dependency we probably need to keep close to latest. I'm a bit surprised that it doesn't work though - have you asked around in the jupyter-latex repository? Maybe this is a bug?

[trybik]

I fully agree, but no other versions combination would work w/ repo2docker (fails at extension installation step). I didn't ask at jupyter-latex, because I believe this is a repo2docker (base image / conda) issue rather than jupyter-latex, as I had it working fine w/ jpuyterlab>=1.2,<2.0 in own Docker image.

(Also note that: jupyter-latex Python requirements for binder are even lower.)

As it seems to be something a bit harder to tackle upstream the toolchain I hoped I could leave it here, at least sharing my discoveries/fixes via this PR.

[choldgraf]

hmmm - well if it's a repo2docker issue then we should be able to resolve it with the right config files. All repo2docker is doing is starting with a super minimal base enviornment, and then just installing things on top of it, so we should be able to get wherever we need to that way.

Considering that the jupyter-latex environment is pinned to lab <1.0, perhaps it only works with lab <1.0? If that's the case then I'm fine merging this in as-is.

[trybik]

I'm positive that jupyterlab_latex==1.0.0 works with
jupyterlab==1.2.6 in ubuntu:bionic base image, and I would bet that jupyterlab_latex>=2.0 works with jupyterlab>=2.0, but did not test that myself.

My bet is on issues w/ conda(?) installing first jupyterlab==1.2.6 which is then uninstalled as you can see in the attached logs, but probably creates some already installed deps issues. There are no logs for lab >=2.0, but the error was the same as for >=1.0,<2.0. Please note that >=1.0,<2.0 logs is from when there was still jupyter lab build in postBuild, which seems unnecessary (build seems to be done implicitly pre extension installation; fails also when explicitly called).
JupyterLab<1.0.zip
JupyterLab>=1.0,<2.0.zip

[trybik]

Some updates:

• same lab build error occurs when using default jupyterlab==1.2.6 as provided by repo2docker (i.e. when not specifying jupterlab in conda env file).
• my bet was wrong: this has something to do w/ the update of the nodejs/npm toolchain (as used by jupter/lab/staging rather than conda installing jupyterlab - so IMVHO a jupyterlab issue (not jupterlab-latex or repo2docker one). For ref. attached a build log from running jupyter labextension install @jupyterlab/latex in the repo2docker container (w/ unpinned lab and latex ext versions, but you get the same with 1.x):
  jupyterlab-debug-co7idaxq.log
  • side note: someone asked yesterday at SO a similar Q w/ a bit different error message (no answer yet)

[choldgraf]

hmmmm - is it worth raising this issue to the attention of the jupyterlab folks then? Unfortunately it means that I am not very well-qualified to debug since I'm not a great javascript person :-/

[trybik]

Me neither, but also I was wrong - it is @jupyterlab/latex extension issue, jupyterlab builds fine w/o jupyterlab_latex installed via pip. (As an excuse: the JS error is confusing.)

Possibly related (unresolved) issue: jupyterlab/jupyterlab-latex#135 , but different error message and concerns only ver. 2.0, not 1.0.

[choldgraf]

hmmmm...I am not sure what's the right path forward there :-/

[trybik]

I would propose:

1. accept this PR to have a working repo
   • anyway IMVHO the value is in the apt.txt, which is linked on Binder requirements specs as LaTeX example
2. open "unpin jupyterlab & jupyterlab_latex" issue, and resolve it once the jupyterlab_latex build issues are resolved

The viable alternatively IMVHO is to reject this PR and:

1. remove jupyterlab_latex and fall back on Update to Include JuptyerLab/Latex? #4, to be resolved once the jupyterlab_latex build issues are resolved
2. include fixes of other independent issues from here:
   • extended (improved) apt packages list,
   • unnecessary jupyter lab build call,
   • missing figure

[choldgraf]

Thanks for the thoughtful explanation - Wanna open up an issue that describes the problem you mentioned above, and then I'll give this a merge?

[trybik]

Done: #10

[choldgraf]

great - thanks so much for following up on this one 👍