feat(log): make console_logger() accept RUSTUP_TERM_COLOR and NO_COLOR

Author: rami3l

src/cli/log.rs

@@ -65,7 +65,16 @@ where
     S: Subscriber + for<'span> LookupSpan<'span>,
 {
     let maybe_rust_log_directives = process.var_os("RUST_LOG").clone();
-    let has_ansi = process.stderr().is_a_tty();
+    let has_ansi = {
+        let env_override = process.var("RUSTUP_TERM_COLOR").map(|it| it.to_lowercase());
+        match env_override.as_deref() {
+            Ok("always") => true,
+            Ok("never") => false,
+            // `RUSTUP_TERM_COLOR` is prioritized over `NO_COLOR`.
+            _ if process.var("NO_COLOR").is_ok() => false,
+            _ => process.stderr().is_a_tty(),
+        }
+    };
     let logger = tracing_subscriber::fmt::layer()
         .with_writer(move || process.stderr())
         .with_ansi(has_ansi);