fix(container): remove legacy compose FFI

changelog.d/8441-remove-legacy-compose-ffi.md

@@ -0,0 +1,6 @@
+### Fixed
+
+- Removed `perry-container-compose`'s unused legacy `ffi` feature and duplicate
+  `js_compose_*` exports, which implemented a 4-byte string header incompatible
+  with the runtime's 20-byte string ABI. Compose FFI remains available through
+  the canonical stack-handle exports in `perry-stdlib`.

crates/perry-container-compose/Cargo.toml

@@ -40,8 +40,6 @@ proptest = "1"
 
 [features]
 default = []
-ffi = []  # Enable FFI exports for Perry TypeScript integration (legacy YAML-path shape;
-          # do NOT combine with perry-stdlib container feature — would link-collide)
 # Live-runtime integration tests (require a real OCI runtime). The
 # functional tests under tests/functional_orchestration.rs need
 # `MockBackend` exposed, so this implies `test-utils`.

crates/perry-container-compose/src/lib.rs

@@ -24,14 +24,6 @@ pub mod yaml;
 #[cfg(any(test, feature = "test-utils"))]
 pub mod testing;
 
-// FFI exports (Perry TypeScript integration). NOTE: when this crate is
-// consumed by perry-stdlib (the canonical FFI host), the `ffi` feature
-// must NOT be enabled — perry-stdlib publishes a different (canonical
-// SPEC §9.1, stack-handle based) `js_compose_*` shape that would collide
-// at link with this module's legacy YAML-file-path shape.
-#[cfg(feature = "ffi")]
-pub mod ffi;
-
 // Re-exports
 pub use backend::{
     detect_backend, platform_candidates, probe_all_candidates, AppleContainerProtocol,

crates/perry-container-compose/tests/legacy_ffi_removed.rs

@@ -0,0 +1,35 @@
+use std::path::Path;
+
+#[test]
+fn legacy_ffi_surface_stays_removed() {
+    let crate_dir = Path::new(env!("CARGO_MANIFEST_DIR"));
+    let manifest = std::fs::read_to_string(crate_dir.join("Cargo.toml"))
+        .expect("read perry-container-compose Cargo.toml");
+    let features = manifest
+        .split_once("[features]")
+        .expect("manifest has a features table")
+        .1
+        .split("\n[")
+        .next()
+        .expect("features table has contents");
+
+    assert!(
+        !features.lines().any(|line| {
+            line.split('#')
+                .next()
+                .is_some_and(|entry| entry.trim_start().starts_with("ffi ="))
+        }),
+        "the legacy `ffi` feature must not be reintroduced; perry-stdlib owns the canonical compose FFI"
+    );
+
+    let lib = std::fs::read_to_string(crate_dir.join("src/lib.rs"))
+        .expect("read perry-container-compose src/lib.rs");
+    assert!(
+        !lib.contains("feature = \"ffi\""),
+        "src/lib.rs must not gate a module on the removed legacy `ffi` feature"
+    );
+    assert!(
+        !crate_dir.join("src/ffi.rs").exists(),
+        "the duplicate legacy compose FFI module must stay deleted"
+    );
+}

crates/perry-stdlib/Cargo.toml

@@ -339,11 +339,6 @@ perry-updater = { workspace = true }
 # entry is still required for `cargo build -p perry-container-compose`
 # to succeed — that's enforced by the `crate_in_workspace_members` test
 # in this crate's tests/.
-#
-# NOTE 2: do NOT enable the crate's own `ffi` feature here — it exports
-# a *different* legacy `js_compose_*` shape (YAML-file-path-based) that
-# would collide with stdlib's canonical SPEC §9.1 stack-handle
-# signatures at link.
 perry-container-compose = { path = "../perry-container-compose", optional = true }
 
 thiserror.workspace = true