Serial monitor extension shows blank pane

[IvanVeloz]

Using this version of VScode, the Serial Monitor extension (ms-vscode.vscode-serial-monitor) shows a blank pane as seen below. Normally it should look like the animation shown on the marketplace.

I found these logs by Ctrl+Shift+P then "Developer: Show Logs..." then "Serial Monitor Logging".

2024-10-18T15:39:40.465Z [info] [vscode-serial-monitor] Activating extension
2024-10-18T15:39:43.440Z [debug] [vscode-serial-monitor.monitor] VsCodeHostAdapter [webview -> host]: {"service":"monitorHost","type":"initialize","kind":"request","messageId":0}
2024-10-18T15:39:43.450Z [debug] [vscode-serial-monitor.monitor] VsCodeHostAdapter [webview <- host]: {"service":"monitorHost","type":"initialize","kind":"exception","messageId":0,"payload":{"message":"spawn udevadm ENOENT","stack":"Error: spawn udevadm ENOENT\n\tat ChildProcess._handle.onexit (node:internal/child_process:286:19)\n\tat onErrorNT (node:internal/child_process:484:16)\n\tat process.processTicksAndRejections (node:internal/process/task_queues:82:21)","errno":-2,"code":"ENOENT","syscall":"spawn udevadm","path":"udevadm","spawnargs":["info","-e"]}}
2024-10-18T15:39:43.451Z [error] [vscode-serial-monitor.monitor] Failed to initialize serial monitor view {"message":"spawn udevadm ENOENT","stack":"Error: spawn udevadm ENOENT\n\tat ChildProcess._handle.onexit (node:internal/child_process:286:19)\n\tat onErrorNT (node:internal/child_process:484:16)\n\tat process.processTicksAndRejections (node:internal/process/task_queues:82:21)","errno":-2,"code":"ENOENT","syscall":"spawn udevadm","path":"udevadm","spawnargs":["info","-e"]}

[IvanVeloz]

I think the extension is trying to call udevadm, a command, and that is not included in the flatpak:

sh-5.2$ udevadm
sh: udevadm: command not found

If I try it on the host then:

ivan@ivan-pc:~$ udevadm
Command verb required (one of info, trigger, settle, control, monitor, hwdb, test, test-builtin, wait, lock, verify, version, help).

Presumably, the extension uses udevadm to scan for serial ports and their names.

[IvanVeloz]

A workaround:

• Create a file touch $HOME/.var/app/com.visualstudio.code/data/node_modules/bin/udevadm.
• Edit its contents:

#!/bin/sh
flatpak-spawn --host udevadm "$@"

• Make it executable: chmod +x $HOME/.var/app/com.visualstudio.code/data/node_modules/bin/udevadm
• Reopen VScode.

I believe no permission changes are necessary (i.e. no changes on Flatseal or equivalents).