jupyter install failure docker container build

[deeprave]

i am attempting to build a Docker container with jupyterlab + notebook + r + this drawio extension. It is based on the Dockerfile for anaconda3 from hub.docker.com.

NodeJS 10.15.2
Npm 5.8.0

(these are both installed with current jupyterlab apparently)

$ jupyter -v

jupyter core     : 4.5.0
jupyter-notebook : 6.0.1
qtconsole        : 4.5.5
ipython          : 7.8.0
ipykernel        : 5.1.2
jupyter client   : 5.3.3
jupyter lab      : 1.1.4
nbconvert        : 5.6.0
ipywidgets       : 7.5.1
nbformat         : 4.4.0
traitlets        : 4.3.3

Failure message as follows:

jupyter labextension install jupyterlab-drawio
Building jupyterlab assets (build:prod:minimize)
An error occured.
RuntimeError: JupyterLab failed to build
See the log file for details:  /tmp/jupyterlab-debug-3uijdxha.log

/tmp/jupyterlab-debug-3uijdxha.log contains:

Building jupyterlab assets (build:prod:minimize)
> node /opt/conda/lib/python3.7/site-packages/jupyterlab/staging/yarn.js install --non-interactive
yarn install v1.15.2
[1/5] Validating package.json...
[2/5] Resolving packages...
[3/5] Fetching packages...
info fsevents@1.2.9: The platform "linux" is incompatible with this module.
info "fsevents@1.2.9" is an optional dependency and failed compatibility check. Excluding it from installation.
[4/5] Linking dependencies...
[5/5] Building fresh packages...
success Saved lockfile.
Done in 11.36s.

> node /opt/conda/lib/python3.7/site-packages/jupyterlab/staging/yarn.js yarn-deduplicate -s fewer
yarn run v1.15.2
$ /opt/conda/share/jupyter/lab/staging/node_modules/.bin/yarn-deduplicate -s fewer
Done in 0.99s.

> node /opt/conda/lib/python3.7/site-packages/jupyterlab/staging/yarn.js run build:prod:minimize
yarn run v1.15.2
$ cross-env NODE_OPTIONS=--max_old_space_size=4096 webpack --config webpack.prod.minimize.config.js
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

JupyterLab failed to build
Traceback (most recent call last):

  File "/opt/conda/lib/python3.7/site-packages/jupyterlab/debuglog.py", line 47, in debug_logging
    yield

  File "/opt/conda/lib/python3.7/site-packages/jupyterlab/labextensions.py", line 105, in start
    core_config=self.core_config)

  File "/opt/conda/lib/python3.7/site-packages/jupyterlab/commands.py", line 378, in build
    command=command, clean_staging=clean_staging)

  File "/opt/conda/lib/python3.7/site-packages/jupyterlab/commands.py", line 583, in build
    raise RuntimeError(msg)

RuntimeError: JupyterLab failed to build

Exiting application: jupyter

/opt/conda/lib/python3.7/site-packages/jupyterlab/staging/webpack.prod.minimize.config.js

const TerserPlugin = require('terser-webpack-plugin');
var merge = require('webpack-merge');
var config = require('./webpack.config');

config[0] = merge(config[0], {
  mode: 'production',
  devtool: 'source-map',
  optimization: {
    minimizer: [
      new TerserPlugin({
        parallel: true,
        sourceMap: true,
        terserOptions: {
          compress: false,
          ecma: 6,
          mangle: true,
          output: {
            beautify: false,
            comments: false
          },
          safari10: true
        },
        cache: process.platform !== 'win32'
      })
    ]
  }
});

module.exports = config;

[deeprave]

Digging into this a little further I tried building a dev installation within the container:
after the npm build aI get:

#  jupyter labextension link .
Installing /opt/conda/lib/python3.7/site-packages/jupyterlab/staging as a linked package because it does not have extension metadata:
   `mimeExtension` and `extension` must point to different modules
Building jupyterlab assets (build:dev:minimize)