filter log messages from the library separately

topiary-cli/Cargo.toml

@@ -20,7 +20,7 @@ readme.workspace = true
 license.workspace = true
 
 [[bin]]
-name = "topiary"
+name = "topiary_cli"
 path = "src/main.rs"
 
 [dependencies]

topiary-cli/src/cli.rs

@@ -184,15 +184,20 @@ pub fn get_args() -> CLIResult<Cli> {
     let mut args = Cli::parse();
 
     // This is the earliest point that we can initialise the logger, from the --verbose flags,
-    // before any fallible operations have started
+    // before any fallible operations have started.
+    //
+    // Be more strict with logs coming with the library; prefer to display less of them.
+    let (global_filter_level, library_filter_level) = match args.global.verbose {
+        0 => (LevelFilter::Error, LevelFilter::Error),
+        1 => (LevelFilter::Warn, LevelFilter::Warn),
+        2 => (LevelFilter::Info, LevelFilter::Warn),
+        3 => (LevelFilter::Debug, LevelFilter::Warn),
+        _ => (LevelFilter::Trace, LevelFilter::Trace),
+    };
+
     env_logger::Builder::new()
-        .filter_level(match args.global.verbose {
-            0 => LevelFilter::Error,
-            1 => LevelFilter::Warn,
-            2 => LevelFilter::Info,
-            3 => LevelFilter::Debug,
-            _ => LevelFilter::Trace,
-        })
+        .filter_level(global_filter_level)
+        .filter_module("topiary", library_filter_level)
         .init();
 
     // NOTE We do not check that input files are actual files (with Path::is_file), because that