reinstall: avoid duplicate users in loginctl_users

See #1093

Signed-off-by: Omer Tuchfeld <[email protected]>

system-reinstall-bootc/src/users.rs

@@ -5,12 +5,13 @@ use rustix::process::geteuid;
 use rustix::process::getuid;
 use rustix::thread::set_thread_res_uid;
 use serde_json::Value;
+use std::collections::HashSet;
 use std::fmt::Display;
 use std::fmt::Formatter;
 use std::process::Command;
 use uzers::os::unix::UserExt;
 
-fn loginctl_users() -> Result<Vec<String>> {
+fn loginctl_users() -> Result<HashSet<String>> {
     let users: Value = Command::new("loginctl")
         .arg("list-sessions")
         .arg("--output")
@@ -32,10 +33,10 @@ fn loginctl_users() -> Result<Vec<String>> {
                 .context("user name field is not a string")
                 .map(String::from)
         })
-        // Artificially add the root user to the list of users as it doesn't appear in loginctl
-        // list-sessions
+        // Artificially add the root user to the list of users as it doesn't always appear in
+        // `loginctl list-sessions`
         .chain(std::iter::once(Ok("root".to_string())))
-        .collect::<Result<Vec<String>>>()
+        .collect::<Result<HashSet<String>>>()
         .context("error parsing users")
 }