feat(moq-tokio,moq-ffi)!: always log to logcat on Android

.github/workflows/android.yml

@@ -11,9 +11,13 @@ name: Android
 # recipe is still `just rs android`, so a local run and this one compile the
 # same thing, and rust-toolchain.toml still pins the compiler.
 #
+# It also builds moq-ffi and asserts the `.so` imports `__android_log_*`, so a
+# build that stops linking logcat fails here.
+#
 # Narrow trigger, like wasm.yml. The filter is moq-video's in-repo dependency
-# graph (`cargo metadata`, normal dependencies), plus the files that decide how
-# it is built. A crate added to that graph has to be added here too.
+# graph (`cargo metadata`, normal dependencies), plus moq-ffi and moq-tokio, which
+# own the logcat link, and the files that decide how it is built. A crate added
+# to that graph has to be added here too.
 
 permissions:
   contents: read
@@ -25,6 +29,8 @@ on:
     types: [opened, synchronize, reopened, closed]
     paths:
       - "rs/moq-video/**"
+      - "rs/moq-ffi/**"
+      - "rs/moq-tokio/**"
       - "rs/moq-mux/**"
       - "rs/moq-net/**"
       - "rs/moq-nvenc/**"

quest/m1/README.md

@@ -31,7 +31,6 @@ QUIC studies there on that rule.
 - [Merge queue](/quest/m1/merge-queue.md) - the required checks run on `merge_group`, so a stale green check can no longer break main
 - [Binding audio delay](/quest/m1/binding-surface.md) - moq-ffi and every wrapper configure and observe audio playout delay
 - [FFI shape](/quest/m1/ffi-shape/README.md) - the bindings mirror Rust's layers: net at the root, then media, json, flate, audio, and video namespaces built from the handle below
-- [Android logcat](/quest/m1/android-logcat.md) - on dev, Android builds always log to logcat and the `android-logcat` feature is gone
 - [Raw stream codes](/quest/m1/raw-stream-codes.md) - raw QUIC stream resets and stops carry the application's code, not an HTTP/3-mapped one
 - [IETF drain before close](/quest/m1/ietf-drain-before-close.md) - moq-transport sessions deliver finished tracks before a graceful close, as moq-lite does
 - [Close waits for the tail](/quest/m1/close-tail.md) - on lite-07, `close()` returns `Ok` only after each subscriber FINs its Subscribe Stream, having read the track to its end

rs/justfile

@@ -127,10 +127,13 @@ capture-test *args:
 # than a denying clippy: the capture plumbing is dead on a target without a
 # capture backend.
 
-# Compile the Android backends, which the host-target check skips.
+# Compile the Android backends, which the host-target check skips, and assert the
+# moq-ffi library links logcat: `Log::init` is silent on Android without it.
 [positional-arguments]
 android *args:
     cargo ndk -t arm64-v8a --platform 26 check --locked -p moq-video --all-targets "$@"
+    cargo ndk -t arm64-v8a --platform 26 -o target/android-jni build --locked -p moq-ffi "$@"
+    nm -D --undefined-only target/android-jni/arm64-v8a/libmoq_ffi.so | grep -q __android_log_
 
 # moq-wasm's crate root is `#![cfg(target_arch = "wasm32")]`, so only a wasm32
 # build sees the code. Not to be confused with `just js wasm`, which builds the

rs/moq-ffi/Cargo.toml

@@ -26,7 +26,6 @@ crate-type = ["staticlib", "cdylib"]
 # They are unavailable on wasm32 regardless: the browser encodes via WebCodecs.
 default = ["audio", "video"]
 
-android-logcat = ["moq-tokio/android-logcat"]
 audio = ["dep:moq-audio"]
 video = ["dep:moq-video", "dep:pollster"]
 

rs/moq-tokio/Cargo.toml

@@ -45,7 +45,6 @@ tcp = ["_transport", "dep:qmux", "dep:dns-lookup"]
 # inspection on accept. Pulls in `tcp` (shares qmux's stream transport).
 uds = ["tcp", "qmux/uds"]
 ring = ["_certs", "rustls/ring", "rcgen/ring", "web-transport-moq?/ring"]
-android-logcat = ["dep:tracing-android"]
 
 [dependencies]
 bytes = "1"
@@ -98,7 +97,7 @@ x509-parser = "0.18"
 # `tls::init_android`); jni is the bridge. Until init runs, verification falls
 # back to the bundled Mozilla roots.
 jni = "0.22"
-tracing-android = { version = "0.2", optional = true }
+tracing-android = "0.2"
 webpki-roots = "1"
 
 [target.'cfg(unix)'.dependencies]

rs/moq-tokio/src/log.rs

@@ -66,15 +66,15 @@ impl Log {
 
 		// On Android, route logs to logcat so they can be inspected via ADB/Android Studio.
 		// Everywhere else, format to stderr.
-		#[cfg(all(target_os = "android", feature = "android-logcat"))]
+		#[cfg(target_os = "android")]
 		let registry = {
 			let logcat_layer = tracing_android::layer("MoQNative")
 				.map_err(|e| crate::Error::Logcat(std::sync::Arc::new(e)))?
 				.with_filter(filter);
 			registry.with(logcat_layer)
 		};
 
-		#[cfg(not(all(target_os = "android", feature = "android-logcat")))]
+		#[cfg(not(target_os = "android"))]
 		let registry = {
 			let fmt_layer = tracing_subscriber::fmt::layer()
 				.with_writer(std::io::stderr)