doc: Point to methods on Command as alternatives to set/remove_var

Author: clubby789

library/std/src/env.rs

@@ -336,7 +336,10 @@ impl Error for VarError {
 ///  - [Austin Group Bugzilla](https://austingroupbugs.net/view.php?id=188)
 ///  - [GNU C library Bugzilla](https://sourceware.org/bugzilla/show_bug.cgi?id=15607#c2)
 ///
+/// To pass an environment variable to a child process, you can instead use [`Command::env`].
+///
 /// [`std::net::ToSocketAddrs`]: crate::net::ToSocketAddrs
+/// [`Command::env`]: crate::process::Command::env
 ///
 /// # Panics
 ///
@@ -396,7 +399,12 @@ pub unsafe fn set_var<K: AsRef<OsStr>, V: AsRef<OsStr>>(key: K, value: V) {
 ///  - [Austin Group Bugzilla](https://austingroupbugs.net/view.php?id=188)
 ///  - [GNU C library Bugzilla](https://sourceware.org/bugzilla/show_bug.cgi?id=15607#c2)
 ///
+/// To prevent a child process from inheriting an environment variable, you can
+/// instead use [`Command::env_remove`] or [`Command::env_clear`].
+///
 /// [`std::net::ToSocketAddrs`]: crate::net::ToSocketAddrs
+/// [`Command::env_remove`]: crate::process::Command::env_remove
+/// [`Command::env_clear`]: crate::process::Command::env_clear
 ///
 /// # Panics
 ///