userns check

[jfgordon2]

Closes #222

Description

Check for userns prior to launching github desktop, allow user to choose to run with sandbox disabled

Screenshots

Release notes

Notes: Added prelaunch script to allow a check for user namespace and potentially other future checks

[shiftkey]

This is an interesting idea, but I'd like to better understand how/why Desktop is causing this crash. I was able to confirm yesterday a plain Electron app worked fine with this setting disabled, and was digging into what this setting is actually enforcing on the renderer process (which I believe is being subjected to the sandboxing that relies on this setting) is what I'd like to answer before we go further.

[jfgordon2]

Ah, of course. Let me know if I can do anything to help.

[shiftkey]

Closing this out now that we know the root cause, and should not require the user change their setup or disable the sandboxing: #222 (comment)