Initial support for randomized environment variables

src/hyperfine/benchmark.rs

@@ -47,20 +47,19 @@ pub fn time_shell_command(
     failure_action: CmdFailureAction,
     shell_spawning_time: Option<TimingResult>,
 ) -> io::Result<(TimingResult, bool)> {
-    let wallclock_timer = WallClockTimer::start();
-
     let (stdout, stderr) = if show_output {
         (Stdio::inherit(), Stdio::inherit())
     } else {
         (Stdio::null(), Stdio::null())
     };
+
+    let wallclock_timer = WallClockTimer::start();
     let result = execute_and_time(stdout, stderr, &command.get_shell_command(), shell)?;
+    let mut time_real = wallclock_timer.stop();
 
     let mut time_user = result.user_time;
     let mut time_system = result.system_time;
 
-    let mut time_real = wallclock_timer.stop();
-
     if failure_action == CmdFailureAction::RaiseError && !result.status.success() {
         return Err(io::Error::new(
             io::ErrorKind::Other,

src/hyperfine/shell.rs

@@ -69,6 +69,10 @@ fn run_shell_command(
     Command::new(shell)
         .arg("-c")
         .arg(command)
+        .env(
+            "HYPERFINE_RANDOMIZED_ENVIRONMENT_OFFSET",
+            "X".repeat(rand::random::<usize>() % 4096usize),
+        )
         .stdin(Stdio::null())
         .stdout(stdout)
         .stderr(stderr)