Enable logging in rustls and tracing-using dependencies

Enable `rustls`'s `logging` feature to start emitting logs.

Enable the `tracing` crate's `log` feature to hook up the dependencies
that log via that crate.

`hyper` can use `tracing` but it's currently unstable and locked
behind `RUSTFLAGS='--cfg hyper_unstable_tracing'` so we shouldn't use
it yet.

This partially addresses ducaale#389.

```console
$ RUST_LOG=trace/ALPN xh https://example.org
[0.495665s DEBUG rustls::client::hs] ALPN protocol is Some(b"h2")
[0.499526s TRACE hyper_util::client::legacy::client] ALPN negotiated h2, updating pool
HTTP/2.0 200 OK
[...]
$ RUST_LOG=rustls xh https://example.org
[0.288085s DEBUG rustls::client::hs] No cached session for DnsName("example.org")
[0.288657s DEBUG rustls::client::hs] Not resuming any session
[0.288767s TRACE rustls::client::hs] Sending ClientHello Message {
    version: TLSv1_0,
    payload: Handshake {
[...]
[0.698465s DEBUG rustls::client::hs] Using ciphersuite TLS13_AES_256_GCM_SHA384
[0.698508s DEBUG rustls::client::tls13] Not resuming
[0.698530s TRACE rustls::client::client_conn] EarlyData rejected
[0.699267s DEBUG rustls::client::tls13] TLS1.3 encrypted extensions: [Protocols([ProtocolName(6832)])]
[0.699342s DEBUG rustls::client::hs] ALPN protocol is Some(b"h2")
[0.699578s TRACE rustls::client::tls13] Server cert is
CertificateChain([CertificateDer(0x3082076e3082[...]
```

`native-tls` barely has any logging so we don't get much useful info
from there yet.

Author: blyxxyz

Cargo.lock

@@ -26,6 +26,7 @@ dirs = "5.0"
 encoding_rs = "0.8.28"
 encoding_rs_io = "0.1.7"
 flate2 = "1.0.22"
+# Add "tracing" feature to hyper once it stabilizes
 hyper = { version = "1.2", default-features = false }
 indicatif = "0.17"
 jsonxf = "1.1.0"
@@ -52,6 +53,11 @@ ruzstd = { version = "0.7", default-features = false, features = ["std"]}
 env_logger = { version = "0.11.3", default-features = false, features = ["color", "auto-color", "humantime"] }
 log = "0.4.21"
 
+# Enable logging in transitive dependencies.
+# The rustls version number should be kept in sync with hyper/reqwest.
+rustls = { version = "0.23.14", optional = true, default-features = false, features = ["logging"] }
+tracing = { version = "0.1.41", default-features = false, features = ["log"] }
+
 [dependencies.reqwest]
 version = "0.12.3"
 default-features = false
@@ -85,7 +91,7 @@ http-body-util = "0.1.1"
 [features]
 default = ["online-tests", "rustls", "network-interface"]
 native-tls = ["reqwest/native-tls", "reqwest/native-tls-alpn"]
-rustls = ["reqwest/rustls-tls", "reqwest/rustls-tls-webpki-roots", "reqwest/rustls-tls-native-roots"]
+rustls = ["reqwest/rustls-tls", "reqwest/rustls-tls-webpki-roots", "reqwest/rustls-tls-native-roots", "dep:rustls"]
 
 # To be used by platforms that don't support binding to interface via SO_BINDTODEVICE
 # Ideally, this would be auto-disabled on platforms that don't need it

Cargo.toml

@@ -124,3 +124,23 @@ fn warning_for_non_utf8_redirect() {
         .assert()
         .stderr("xh: warning: Redirect to invalid URL: \"\\xff\"\n");
 }
+
+/// This test should fail if rustls's version gets out of sync in Cargo.toml.
+#[cfg(feature = "rustls")]
+#[test]
+fn rustls_emits_logs() {
+    let mut server = server::http(|_req| async move {
+        unreachable!();
+    });
+    server.disable_hit_checks();
+    let cmd = get_command()
+        .arg("--debug")
+        .arg(&server.base_url().replace("http://", "https://"))
+        .env_remove("RUST_LOG")
+        .assert()
+        .failure();
+
+    assert!(std::str::from_utf8(&cmd.get_output().stderr)
+        .unwrap()
+        .contains("rustls::"));
+}