Added debug logging option.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -22,10 +22,14 @@ A clear and concise description of what you expected to happen.
 
 **System information:**
  - Distribution:
- - `greetd` version: 
+ - `greetd` version:
  - `tuigreet` version:
  - Installation method (from source, package, binary, etc.):
  - `tuigreet` command line:
 
 **Additional context**
 Add any other context about the problem here.
+
+**Debug log**
+Run `tuigreet` with the `-d [FILE]` option to log tracing information into the
+specified file, to append here.

Cargo.toml

@@ -41,6 +41,9 @@ unic-langid = "^0.9"
 zeroize = "^1.3"
 uzers = "0.12"
 rand = "0.8.5"
+tracing-appender = "0.2.3"
+tracing-subscriber = "0.3.18"
+tracing = "0.1.40"
 
 [profile.release]
 lto = true

README.md

@@ -10,6 +10,8 @@ Usage: tuigreet [OPTIONS]
 Options:
     -h, --help          show this usage information
     -v, --version       print version information
+    -d, --debug [FILE]  enable debug logging to the provided file, or to
+                        /tmp/tuigreet.log
     -c, --cmd COMMAND   command to run
     -s, --sessions DIRS colon-separated list of Wayland session paths
         --session-wrapper 'CMD [ARGS]...'

contrib/man/tuigreet-1.scd

@@ -16,6 +16,10 @@ tuigreet - A graphical console greeter for greetd
 *-v, --version*
 	Print program version and exit.
 
+*-d, --debug [FILE]*
+	Enables debug logging to the provided FILE path, or to /tmp/tuigreet.log if no
+	file is specified.
+
 *-c, --cmd CMD*
 	Specify which command to run on successful authentication. This can be
 	overridden by manual selection within *tuigreet*.

src/greeter.rs

@@ -34,6 +34,7 @@ use crate::{
   },
 };
 
+const DEFAULT_LOG_FILE: &str = "/tmp/tuigreet.log";
 const DEFAULT_LOCALE: Locale = Locale::en_US;
 const DEFAULT_ASTERISKS_CHARS: &str = "*";
 // `startx` wants an absolute path to the executable as a first argument.
@@ -91,6 +92,9 @@ impl SecretDisplay {
 
 #[derive(SmartDefault)]
 pub struct Greeter {
+  pub debug: bool,
+  pub logfile: String,
+
   #[default(DEFAULT_LOCALE)]
   pub locale: Locale,
   pub config: Option<Matches>,
@@ -354,6 +358,7 @@ impl Greeter {
 
     opts.optflag("h", "help", "show this usage information");
     opts.optflag("v", "version", "print version information");
+    opts.optflagopt("d", "debug", "enable debug logging to the provided file, or to /tmp/tuigreet.log", "FILE");
     opts.optopt("c", "cmd", "command to run", "COMMAND");
     opts.optopt("s", "sessions", "colon-separated list of Wayland session paths", "DIRS");
     opts.optopt("", "session-wrapper", "wrapper command to initialize the non-X11 session", "'CMD [ARGS]...'");
@@ -419,6 +424,15 @@ impl Greeter {
       }
     }
 
+    if self.config().opt_present("debug") {
+      self.debug = true;
+
+      self.logfile = match self.config().opt_str("debug") {
+        Some(file) => file.to_string(),
+        None => DEFAULT_LOG_FILE.to_string(),
+      }
+    }
+
     if self.config().opt_present("issue") && self.config().opt_present("greeting") {
       eprintln!("Only one of --issue and --greeting may be used at the same time");
       print_usage(opts);
@@ -455,6 +469,8 @@ impl Greeter {
       let max_uid = self.config().opt_str("user-menu-max-uid").and_then(|uid| uid.parse::<u16>().ok());
       let (min_uid, max_uid) = get_min_max_uids(min_uid, max_uid);
 
+      tracing::info!("min/max UIDs are {}/{}", min_uid, max_uid);
+
       if min_uid >= max_uid {
         eprintln!("Minimum UID ({min_uid}) must be less than maximum UID ({max_uid})");
         process::exit(1);
@@ -464,7 +480,9 @@ impl Greeter {
         title: fl!("title_users"),
         options: get_users(min_uid, max_uid),
         selected: 0,
-      }
+      };
+
+      tracing::info!("found {} users", self.users.options.len());
     }
 
     if self.config().opt_present("remember-session") && self.config().opt_present("remember-user-session") {

src/info.rs

@@ -229,6 +229,8 @@ pub fn get_sessions(greeter: &Greeter) -> Result<Vec<Session>, Box<dyn Error>> {
 
   files.sort_by(|a, b| a.name.cmp(&b.name));
 
+  tracing::info!("found {} sessions", files.len());
+
   Ok(files)
 }