Terminal in Jupyter does not allow @ / Option modifier for German / Swiss Mac keyboard

[norandom]

Description

Option key combinations do not work in JupyterLab terminal (both left and right Option keys are affected).

This prevents typing essential characters on German keyboard layout:

• @ (Option + L)
• € (Option + E)
• [ (Option + 5)
• ] (Option + 6)
• | (Option + 7)
• { (Option + 8)
• } (Option + 9)

Version: JupyterLab 4.4.10 / Notebook 7.4.7

Root Cause

This is a known bug in JupyterLab tracked in:

• JupyterLab Issue #15744
• JupyterLab Issue #7704

The terminal's xterm.js implementation does not properly honor the macOptionIsMeta setting, causing Option key combinations to be intercepted before they reach the shell.

Reproduce

Open Jupyter Notebook, start Notebook. Keys work. Start Terminal. None work

Expected behavior

@ , |{}≠ should work

Context

• Mac Keyboard (German, Swiss)
• Modifiers Option (left and right)
• Go to NB
• Open Terminal
• no modifiers

Details

The following workaround do not work:

1. JupyterLab Terminal Settings

File: jupyter-settings/@jupyterlab/terminal-extension/plugin.jupyterlab-settings

{
  "macOptionIsMeta": false,
  "macOptionClickForcesSelection": false,
  "altClickMovesCursor": false
}

2. JupyterLab Settings Overrides

File: overrides.json

{
  "@jupyterlab/terminal-extension:plugin": {
    "macOptionIsMeta": false
  }
}

[RRosio]

Hi @norandom thank you for opening this issue. This has been reported in the JupyterLab repository: jupyterlab/jupyterlab#16489. This issue can remain open and we can track issue alongside the JupyterLab issue.

[norandom]

cat ~/.inputrc
# GNU Readline configuration for German keyboard on macOS
# Fixes Option key combinations in JupyterLab terminal
# See: https://github.com/jupyterlab/jupyterlab/issues/16489

# Option + numbers (special characters)
"\e5": "["
"\e6": "]"
"\e7": "|"
"\e8": "{"
"\e9": "}"

# Option + letters (common special characters)
"\el": "@"
"\ee": "€"

For Bash, this workaround works. For ZSH it will not due to zle.