avoid env var forwarding logic panicking for non-UTF-8 env vars

src/shims/env.rs

@@ -50,10 +50,10 @@ pub(crate) fn init<'mir>(
 
         // Skip the loop entirely if we don't want to forward anything.
         if ecx.machine.communicate() || !forwarded_env_vars.is_empty() {
-            for (name, value) in env::vars() {
+            for (name, value) in env::vars_os() {
                 let forward = match ecx.machine.communicate() {
-                    true => !excluded_env_vars.contains(&name),
-                    false => forwarded_env_vars.contains(&name),
+                    true => !excluded_env_vars.iter().any(|v| v.as_str() == &name),
+                    false => forwarded_env_vars.iter().any(|v| v.as_str() == &name),
                 };
                 if forward {
                     let var_ptr = match target_os {