Fix test suit

codex-rs/core/tests/prompt_harness_bin.rs

@@ -2,6 +2,7 @@ use std::error::Error;
 use std::fs;
 
 use assert_cmd::Command;
+use core_test_support::load_sse_fixture_with_id;
 use tempfile::TempDir;
 
 #[test]
@@ -13,11 +14,21 @@ fn prompt_harness_streams_session_event() -> Result<(), Box<dyn Error>> {
     let prompt_path = workspace.path().join("override.md");
     fs::write(&prompt_path, "system override contents")?;
 
+    // Feed the harness from a local SSE fixture so the test never hits the network.
+    let sse_path = workspace.path().join("response.sse");
+    let sse_contents = load_sse_fixture_with_id(
+        "tests/fixtures/completed_template.json",
+        "prompt-harness-response",
+    );
+    fs::write(&sse_path, sse_contents)?;
+
     let script_path = workspace.path().join("driver.py");
     fs::write(&script_path, driver_script())?;
 
     let mut cmd = Command::cargo_bin("prompt_harness")?;
     cmd.env("CODEX_HOME", &codex_home)
+        .env("CODEX_RS_SSE_FIXTURE", &sse_path)
+        .env("OPENAI_API_KEY", "test-key")
         .arg("--system-prompt-file")
         .arg(&prompt_path)
         .arg("python3")