[pitboss/grind] deferred session-0001 (20260520T233019Z-6958)

src/dynamic/lang/ruby.rs

@@ -723,6 +723,8 @@ fn emit_middleware_harness(handler: &str, name: &str) -> HarnessSource {
         r#"{preamble}
 puts "__NYX_MIDDLEWARE__: " + {name:?}
 
+require 'stringio'
+
 # Rack-shape middleware: class with #call(env).
 env = {{
   'REQUEST_METHOD' => 'POST',
@@ -731,7 +733,6 @@ env = {{
   'rack.input' => StringIO.new($nyx_payload),
   'nyx.payload' => $nyx_payload,
 }}
-require 'stringio'
 
 if Object.const_defined?({handler:?})
   cls = Object.const_get({handler:?})
@@ -1233,7 +1234,8 @@ fn invoke_for_shape(spec: &HarnessSpec, shape: RubyShape, entry_fn: &str) -> Str
         RubyShape::RackMiddleware => {
             let cls = entry_class_from_spec(spec);
             format!(
-                r#"  cls = Object.const_defined?({cls:?}) ? Object.const_get({cls:?}) : nil
+                r#"  require 'stringio'
+  cls = Object.const_defined?({cls:?}) ? Object.const_get({cls:?}) : nil
   if cls
     inner = cls.respond_to?(:new) ? (cls.method(:new).arity == 0 ? cls.new : cls.new(nil)) : nil
     env = {{
@@ -1243,7 +1245,6 @@ fn invoke_for_shape(spec: &HarnessSpec, shape: RubyShape, entry_fn: &str) -> Str
       'rack.input' => StringIO.new(($nyx_request[:body] rescue '')),
       'nyx.payload' => $nyx_payload,
     }}
-    require 'stringio'
     status, headers, body = inner.call(env)
     Array(body).each {{ |chunk| print(chunk.to_s) }}
   end"#,

src/dynamic/sandbox/mod.rs

@@ -775,7 +775,20 @@ pub fn run(
             }
         }
         SandboxBackend::Auto => {
-            if docker_available() && harness_is_interpreted(&harness.command) {
+            // Docker containers run the interpreter image's bare runtime
+            // (python:3-slim, node:20-slim, ruby:3-slim, ...) with no
+            // network access under NetworkPolicy::None.  Harness shapes
+            // that depend on packages declared via requirements.txt /
+            // package.json / Gemfile / composer.json can be served from
+            // the host build cache by prepare_*, but the container has
+            // no way to fetch them at exec time.  Route to the process
+            // backend in that case so the harness picks up the host
+            // venv / node_modules / vendor dir already prepared.
+            let needs_host_deps = harness_needs_host_deps(harness);
+            if docker_available()
+                && harness_is_interpreted(&harness.command)
+                && !needs_host_deps
+            {
                 run_docker(harness, payload_bytes, opts)
             } else if docker_available() && harness_is_native_binary(&harness.command) {
                 run_native_binary_docker(harness, payload_bytes, opts)
@@ -788,6 +801,33 @@ pub fn run(
     }
 }
 
+/// True when the harness workdir carries a dependency manifest that the
+/// docker backend has no mechanism to materialise inside the container.
+///
+/// `prepare_python` / `prepare_node` / `prepare_php` / etc. resolve these
+/// against the host build cache before the run, so the process backend
+/// already has a fully-populated venv / node_modules / vendor dir to
+/// invoke.  The docker backend, on the other hand, mounts the workdir
+/// into a bare interpreter image (python:3-slim, node:20-slim, ...) and
+/// runs under `--network=none`, leaving no path for an in-container
+/// `pip install` / `npm install` / `composer install` to fetch the deps.
+/// Routing those shapes to the process backend keeps the verifier honest
+/// on dev hosts where docker is available but the bare image lacks the
+/// third-party libs the entry source imports.
+fn harness_needs_host_deps(harness: &BuiltHarness) -> bool {
+    const MANIFESTS: &[&str] = &[
+        "requirements.txt",
+        "Pipfile.lock",
+        "pyproject.toml",
+        "package.json",
+        "Gemfile",
+        "composer.json",
+    ];
+    MANIFESTS
+        .iter()
+        .any(|name| harness.workdir.join(name).exists())
+}
+
 /// Phase 20 (Track E.4): dispatch the Firecracker backend.
 ///
 /// When `--features firecracker` is off, the call returns