[asveikau]

> The tricky detail is that this means it is unsafe to read/modify the environment through other means, but sometimes this is really hard to avoid.

If you have C and Rust in the same process and C code calls setenv(3), for one ...

Edit: why downvotes? It's very typical to link to C libraries which may call the libc environment stuff ... My point is you can't control library code as easily, if it's some dependency of a dependency eventually calling libc.