ci(linux): use Flutter 3.22.3 for bridge gen (mirrors upstream); 3.24.5 for build

ci/runners/linux/provision.sh

@@ -23,7 +23,8 @@ set -euo pipefail
 
 # ---- pinned versions (mirror .gitea/workflows/build-linux.yml env block) ----
 RUST_VERSION="1.75.0"
-FLUTTER_VERSION="3.24.5"
+FLUTTER_VERSION="3.24.5"        # used for `flutter build linux`
+FLUTTER_BRIDGE_VERSION="3.22.3" # used for `flutter pub get` + flutter_rust_bridge_codegen
 LLVM_VERSION="15.0.6"
 VCPKG_COMMIT="120deac3062162151622ca4860575a33844ba10b"
 RUNNER_VERSION="0.2.11"
@@ -135,18 +136,31 @@ fi
 "$CARGO_HOME/bin/rustup" target add --toolchain "$RUST_VERSION" x86_64-unknown-linux-gnu
 "$CARGO_HOME/bin/rustup" default "$RUST_VERSION"
 
-# ---- 5. Flutter ----
+# ---- 5. Flutter (two SDKs: 3.24.5 for build, 3.22.3 for bridge gen) ----
+# Why two: the bridge codegen (flutter_rust_bridge_codegen 1.80.1 + freezed)
+# produces broken Dart output when run under newer Flutter SDKs on Linux.
+# Upstream's bridge.yml uses 3.22.3 specifically; we mirror that. The .deb
+# build itself uses 3.24.5.
+install_flutter() {
+    local ver="$1" dir="$2"
+    if [[ ! -x "$dir/bin/flutter" ]]; then
+        log "Installing Flutter $ver -> $dir"
+        local tmp; tmp="$(mktemp -d)"
+        local parent; parent="$(dirname "$dir")"
+        curl -fsSL -o "$tmp/flutter.tar.xz" \
+            "https://storage.googleapis.com/flutter_infra_release/releases/stable/linux/flutter_linux_${ver}-stable.tar.xz"
+        # Tarball extracts into a top-level `flutter/` dir; rename to target.
+        tar -xJf "$tmp/flutter.tar.xz" -C "$tmp"
+        mkdir -p "$parent"
+        mv "$tmp/flutter" "$dir"
+        rm -rf "$tmp"
+    fi
+    "$dir/bin/flutter" config --no-analytics >/dev/null
+    "$dir/bin/flutter" precache --linux >/dev/null
+}
+install_flutter "$FLUTTER_VERSION"        /opt/flutter
+install_flutter "$FLUTTER_BRIDGE_VERSION" /opt/flutter-bridge
 FLUTTER_DIR=/opt/flutter
-if [[ ! -x "$FLUTTER_DIR/bin/flutter" ]]; then
-    log "Installing Flutter $FLUTTER_VERSION"
-    tmp="$(mktemp -d)"
-    curl -fsSL -o "$tmp/flutter.tar.xz" \
-        "https://storage.googleapis.com/flutter_infra_release/releases/stable/linux/flutter_linux_${FLUTTER_VERSION}-stable.tar.xz"
-    tar -xJf "$tmp/flutter.tar.xz" -C /opt
-    rm -rf "$tmp"
-fi
-"$FLUTTER_DIR/bin/flutter" config --no-analytics >/dev/null
-"$FLUTTER_DIR/bin/flutter" precache --linux >/dev/null
 
 # ---- 6. vcpkg ----
 VCPKG_DIR=/opt/vcpkg
@@ -170,6 +184,7 @@ chown -R "$SERVICE_USER:$SERVICE_USER" "$RUSTUP_HOME"
 # Flutter SDK: r/x is enough for builds, but `flutter pub get` writes to its
 # own cache subdir so we make it writable as well.
 chown -R "$SERVICE_USER:$SERVICE_USER" "$FLUTTER_DIR"
+chown -R "$SERVICE_USER:$SERVICE_USER" /opt/flutter-bridge
 # vcpkg: builds write under installed/, buildtrees/, etc.
 chown -R "$SERVICE_USER:$SERVICE_USER" "$VCPKG_DIR"
 # LLVM: read+execute is enough; we never write here at build time.