How are you setting that sandbox up? I've laid out numerous constraints - x-platform support is non-existent for sandboxing, sandboxing requires privileges to perform, whole-program sandboxing is fundamentally weaker, maintenance of sandboxing is best done by developers, etc.

> Even if it does, you should expose exactly those particular directories (e.g. ~/.config) and nothing else.

Yes, but now you are in charge of knowing every potential file access, network access, or possibly even system call, for a program that you do not maintain.