同じ状況に立つ人が果たして居るのか分からないので、雑にメモ

環境：
win10
anaconda 4.8.3

#起こった問題

node.jsのカーネルが立たない

>jupyter lab
[I 19:33:43.066 LabApp] JupyterLab extension loaded from C:\ProgramData\Anaconda3\lib\site-packages\jupyterlab
[I 19:33:43.066 LabApp] JupyterLab application directory is C:\ProgramData\Anaconda3\share\jupyter\lab
[I 19:33:43.486 LabApp] Serving notebooks from local directory: C:\Users\fuga
[I 19:33:43.487 LabApp] The Jupyter Notebook is running at:
[I 19:33:43.487 LabApp] http://localhost:8888/
[I 19:33:43.487 LabApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).
[I 19:33:45.892 LabApp] 301 GET /lab/workspaces/auto-Z/?clone (::1) 1.01ms
[I 19:33:47.494 LabApp] Build is up to date
[I 19:33:49.648 LabApp] Creating new notebook in /
[E 19:33:50.113 LabApp] Failed to run command:
    ['ijskernel.cmd', '--hide-undefined', 'C:\\Users\\hoge\\AppData\\Roaming\\jupyter\\runtime\\kernel-6cf3f0a8-3fed-475d-b293-b37723c04594.json', '--protocol=5.0']

当然コードの実行もできない

[E 19:33:52.012 LabApp] Uncaught exception POST /api/sessions?1590748431976 (::1)
    HTTPServerRequest(protocol='http', host='localhost:8888', method='POST', uri='/api/sessions?1590748431976', version='HTTP/1.1', remote_ip='::1')
    Traceback (most recent call last):
      File "C:\ProgramData\Anaconda3\lib\site-packages\tornado\web.py", line 1703, in _execute
        result = await result
      File "C:\ProgramData\Anaconda3\lib\site-packages\tornado\gen.py", line 742, in run
        yielded = self.gen.throw(*exc_info)  # type: ignore
      File "C:\ProgramData\Anaconda3\lib\site-packages\notebook\services\sessions\handlers.py", line 72, in post
        type=mtype))
      File "C:\ProgramData\Anaconda3\lib\site-packages\tornado\gen.py", line 735, in run
        value = future.result()
      File "C:\ProgramData\Anaconda3\lib\site-packages\tornado\gen.py", line 742, in run
        yielded = self.gen.throw(*exc_info)  # type: ignore
      File "C:\ProgramData\Anaconda3\lib\site-packages\notebook\services\sessions\sessionmanager.py", line 88, in create_session
        kernel_id = yield self.start_kernel_for_session(session_id, path, name, type, kernel_name)
      File "C:\ProgramData\Anaconda3\lib\site-packages\tornado\gen.py", line 735, in run
        value = future.result()
      File "C:\ProgramData\Anaconda3\lib\site-packages\tornado\gen.py", line 742, in run
        yielded = self.gen.throw(*exc_info)  # type: ignore
      File "C:\ProgramData\Anaconda3\lib\site-packages\notebook\services\sessions\sessionmanager.py", line 101, in start_kernel_for_session
        self.kernel_manager.start_kernel(path=kernel_path, kernel_name=kernel_name)
      File "C:\ProgramData\Anaconda3\lib\site-packages\tornado\gen.py", line 735, in run
        value = future.result()
      File "C:\ProgramData\Anaconda3\lib\site-packages\tornado\gen.py", line 209, in wrapper
        yielded = next(result)
      File "C:\ProgramData\Anaconda3\lib\site-packages\notebook\services\kernels\kernelmanager.py", line 168, in start_kernel
        super(MappingKernelManager, self).start_kernel(**kwargs)
      File "C:\ProgramData\Anaconda3\lib\site-packages\jupyter_client\multikernelmanager.py", line 158, in start_kernel
        km.start_kernel(**kwargs)
      File "C:\ProgramData\Anaconda3\lib\site-packages\jupyter_client\manager.py", line 305, in start_kernel
        self.kernel = self._launch_kernel(kernel_cmd, **kw)
      File "C:\ProgramData\Anaconda3\lib\site-packages\jupyter_client\manager.py", line 212, in _launch_kernel
        return launch_kernel(kernel_cmd, **kw)
      File "C:\ProgramData\Anaconda3\lib\site-packages\jupyter_client\launcher.py", line 135, in launch_kernel
        proc = Popen(cmd, **kwargs)
      File "C:\ProgramData\Anaconda3\lib\subprocess.py", line 800, in __init__
        restore_signals, start_new_session)
      File "C:\ProgramData\Anaconda3\lib\subprocess.py", line 1207, in _execute_child
        startupinfo)
    FileNotFoundError: [WinError 2] 指定されたファイルが見つかりません。

#治るまでに試したこと事

1. 一応nodeが入っているか確認

>conda install nodejs
>conda update -all

2. karnel.jsonを作り直してみる

>npm install -g ijavascript
>ijsinstall
>jupyter kernelspec list
Available kernels:
  javascript    C:\Users\hoge\AppData\Roaming\jupyter\kernels\javascript
  python3       C:\ProgramData\Anaconda3\share\jupyter\kernels\python3

大丈夫そう

3. ここでjupyter labをまた起動してみると、エラーが見えるようになった

エラーの内容↓

Error: The module '\\?\C:\Program Files (x86)\Nodist\bin\node_modules\ijavascript\node_modules\zeromq\build\Release\zmq.node'
was compiled against a different Node.js version using
NODE_MODULE_VERSION 64. This version of Node.js requires
NODE_MODULE_VERSION 67. Please try re-compiling or re-installing
the module (for instance, using `npm rebuild` or `npm install`).
    at Object.Module._extensions..node (internal/modules/cjs/loader.js:846:18)
    at Module.load (internal/modules/cjs/loader.js:672:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:612:12)
    at Function.Module._load (internal/modules/cjs/loader.js:604:3)
    at Module.require (internal/modules/cjs/loader.js:711:19)
    at require (internal/modules/cjs/helpers.js:14:16)
    at Object.<anonymous> (C:\Program Files (x86)\Nodist\bin\node_modules\ijavascript\node_modules\zeromq\lib\index.js:6:11)
    at Module._compile (internal/modules/cjs/loader.js:805:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:816:10)
    at Module.load (internal/modules/cjs/loader.js:672:32)
[I 19:38:54.040 LabApp] KernelRestarter: restarting kernel (4/5), new random ports
internal/modules/cjs/loader.js:846
  return process.dlopen(module, path.toNamespacedPath(filename));

明らかにnodejsのバージョンが違うよと言われている。
そういえばアップデートした気がする。

NODE_MODULE_VERSION 64. This version of Node.js requires
NODE_MODULE_VERSION 67. Please try re-compiling or re-installing

NODE_MODULE_VERSION が 67だけど、64にしてほしいとのこと

4. nodejsのバージョンを変える

リリース一覧 | Node.js
ここを見に行って、NODE_MODULE_VERSIONが64のものを選ぶ。
私はなんとなく10.12.0にすることにした。
バージョン変更にはもう入れてあったnodistを使った。

>nodist 10.12.0
10.12.0
Installing 10.12.0
 10.12.0 [===============] 24201/24201 KiB 100% 0.0s
Installation successful.

>nodist
  (x64)
  8.16.2
> 10.12.0  (global: 10.12.0)
  11.13.0

5. やれと言われていたリビルドをする。

>jupyter lab build
[LabBuildApp] JupyterLab 1.2.6
[LabBuildApp] Building in C:\ProgramData\Anaconda3\share\jupyter\lab
[LabBuildApp] Building jupyterlab assets (build:prod:minimize)
-

成功したとも失敗したとも出ないが、多分成功している。

6. jupyter labを起動してみる

>jupyter lab

無事実行できた！