Cannot launch any instance if the working directory path contains non-ASCII characters

Since the start of this morning, I’ve spent 45 minutes trying to figure out why the Minecraft launcher stopped launching any Java edition instance oftentimes before any log output is shown in it’s log preview. After a bit of troubleshooting I found out that if I append the following launch parameter, it works again, even if I copy the contents of %appdata%/.minecraft in there

--workdir “S:\Program Files\Minecraft\.minecraft”

The path itself isn’t relevant. If I set something that contains non-ASCII directories, such as “S:\Program Files\Minecraft\těmp“ it stops working again in the exact same way.

This is especially problematic since the launcher by default stores its data in %appdata%\.minecraft which can include non-ASCII characters if you create a local Windows account with a name that contains these characters and you can’t change this without completely recreating a user account. In my case, %userprofile%, a component of %appdata%, is C:\Users\Ondráš. Even worse, you can’t set launch parameters for a MSStore application like the Microsoft store version of the Minecraft launcher.

Since I couldn’t find where the log output is getting saved, I sent a screenshot of the game log instead.

Affected version is 3.40.19-2.6.2, however the version dropdown doesn’t list anything newer than 3.39.31 at the moment This bug didn't occur until the latest build of the launcher.