also print clearing the environment entirely

Author: RalfJung

library/std/src/process/tests.rs

@@ -560,6 +560,29 @@ fn debug_print() {
             "FOO": None,
         }},
     }},
+{PIDFD}}}"#
+        )
+    );
+
+    let mut command_with_cleared_env = Command::new("boring-name");
+    command_with_cleared_env.env_clear().env("BAR", "val").env_remove("FOO");
+    assert_eq!(format!("{command_with_cleared_env:?}"), r#"env -i BAR="val" "boring-name""#);
+    assert_eq!(
+        format!("{command_with_cleared_env:#?}"),
+        format!(
+            r#"Command {{
+    program: "boring-name",
+    args: [
+        "boring-name",
+    ],
+    env: CommandEnv {{
+        clear: true,
+        vars: {{
+            "BAR": Some(
+                "val",
+            ),
+        }},
+    }},
 {PIDFD}}}"#
         )
     );

library/std/src/sys/unix/process/process_common.rs

@@ -558,20 +558,25 @@ impl fmt::Debug for Command {
             if let Some(ref cwd) = self.cwd {
                 write!(f, "cd {cwd:?} && ")?;
             }
-            // Removed env vars need a separate command.
-            // We use a single `unset` command for all of them.
-            let mut any_removed = false;
-            for (key, value_opt) in self.get_envs() {
-                if value_opt.is_none() {
-                    if !any_removed {
-                        write!(f, "unset ")?;
-                        any_removed = true;
+            if self.env.does_clear() {
+                write!(f, "env -i ")?;
+                // Altered env vars will be printed next, that should exactly work as expected.
+            } else {
+                // Removed env vars need a separate command.
+                // We use a single `unset` command for all of them.
+                let mut any_removed = false;
+                for (key, value_opt) in self.get_envs() {
+                    if value_opt.is_none() {
+                        if !any_removed {
+                            write!(f, "unset ")?;
+                            any_removed = true;
+                        }
+                        write!(f, "{} ", key.to_string_lossy())?;
                     }
-                    write!(f, "{} ", key.to_string_lossy())?;
                 }
-            }
-            if any_removed {
-                write!(f, "&& ")?;
+                if any_removed {
+                    write!(f, "&& ")?;
+                }
             }
             // Altered env vars can just be added in front of the program.
             for (key, value_opt) in self.get_envs() {

library/std/src/sys_common/process.rs

@@ -80,6 +80,10 @@ impl CommandEnv {
         self.vars.clear();
     }
 
+    pub fn does_clear(&self) -> bool {
+        self.clear
+    }
+
     pub fn have_changed_path(&self) -> bool {
         self.saw_path || self.clear
     }