fix(opencode): run CLI under a Linux pseudo-TTY so subprocess calls work

researchclaw/pipeline/opencode_bridge.py

@@ -16,8 +16,10 @@
 import logging
 import os
 import re
+import shlex
 import shutil
 import subprocess
+import sys
 import time
 from dataclasses import dataclass, field
 from pathlib import Path
@@ -470,7 +472,7 @@ def _invoke_opencode(
         # Use -m flag to specify model (more reliable than opencode.json)
         resolved_model = self._resolve_opencode_model()
         opencode_cmd = shutil.which("opencode") or "opencode"
-        cmd = [opencode_cmd, "run", "-m", resolved_model, "--format", "json", prompt]
+        cmd = self._build_opencode_command(opencode_cmd, resolved_model, prompt)
 
         t0 = time.monotonic()
         try:
@@ -499,6 +501,38 @@ def _invoke_opencode(
             elapsed = time.monotonic() - t0
             return False, f"Unexpected error: {exc}", elapsed
 
+    @staticmethod
+    def _build_opencode_command(
+        opencode_cmd: str, resolved_model: str, prompt: str
+    ) -> list[str]:
+        """Build the argv for ``opencode run``, wrapping with a pseudo-TTY on Linux.
+
+        The ``opencode`` CLI requires a TTY: when invoked via ``subprocess.run``
+        with piped stdout/stderr it can return exit 0 with empty output and no
+        generated files. On Linux we wrap the call with util-linux
+        ``script -q -e -c "<cmd>" /dev/null`` to provide a pseudo-TTY:
+
+        * ``-q`` suppresses ``script``'s start/done messages,
+        * ``-c`` runs the requested command,
+        * ``-e`` returns the child's exit status (without it ``script`` can
+          return 0 even when the child command fails, which would mask an
+          ``opencode`` failure as success — the very silent-success behaviour
+          this wrapper exists to avoid).
+
+        The wrapper is gated on Linux specifically because the
+        ``script -q -e -c ... /dev/null`` form is util-linux syntax; BSD/macOS
+        ``script`` implementations are not compatible with it. On non-Linux
+        platforms, and when ``script`` is unavailable, we fall back to invoking
+        ``opencode`` directly — i.e. the prior behaviour, no regression.
+        """
+        direct = [opencode_cmd, "run", "-m", resolved_model, "--format", "json", prompt]
+
+        script_path = shutil.which("script")
+        if sys.platform.startswith("linux") and script_path:
+            inner = " ".join(shlex.quote(part) for part in direct)
+            return [script_path, "-q", "-e", "-c", inner, "/dev/null"]
+        return direct
+
     # -- file collection -------------------------------------------------------
 
     @staticmethod

tests/test_opencode_bridge.py

@@ -384,6 +384,97 @@ def test_invoke_opencode_uses_resolved_path(self, tmp_path):
         assert run_mock.call_args.args[0][0].endswith("opencode.cmd")
 
 
+# ============================================================
+# TestBuildOpencodeCommand (PTY wrapper)
+# ============================================================
+
+
+class TestBuildOpencodeCommand:
+    """Tests for _build_opencode_command — Linux pseudo-TTY wrapping."""
+
+    def test_linux_with_script_wraps_in_pty(self):
+        """On Linux with `script` available, wrap via `script -q -e -c <cmd> /dev/null`."""
+        with patch(
+            "researchclaw.pipeline.opencode_bridge.sys.platform", "linux"
+        ), patch(
+            "researchclaw.pipeline.opencode_bridge.shutil.which",
+            return_value="/usr/bin/script",
+        ):
+            cmd = OpenCodeBridge._build_opencode_command(
+                "/usr/bin/opencode", "anthropic/claude-sonnet-4-6", "do the thing"
+            )
+        assert cmd[0] == "/usr/bin/script"
+        assert cmd[1:4] == ["-q", "-e", "-c"]
+        assert cmd[-1] == "/dev/null"
+        # The wrapped inner string must carry the full opencode invocation
+        inner = cmd[4]
+        assert "opencode" in inner
+        assert "run" in inner
+        assert "--format json" in inner
+
+    def test_linux_wrapper_preserves_child_exit_status(self):
+        """The `-e` flag is required: without it `script` can return 0 even when
+        the child command fails, which would mask an opencode failure as success."""
+        with patch(
+            "researchclaw.pipeline.opencode_bridge.sys.platform", "linux"
+        ), patch(
+            "researchclaw.pipeline.opencode_bridge.shutil.which",
+            return_value="/usr/bin/script",
+        ):
+            cmd = OpenCodeBridge._build_opencode_command("/usr/bin/opencode", "m", "p")
+        assert "-e" in cmd
+
+    def test_linux_without_script_falls_back_to_direct(self):
+        """On Linux but `script` missing → direct invocation, no wrapper."""
+        with patch(
+            "researchclaw.pipeline.opencode_bridge.sys.platform", "linux"
+        ), patch(
+            "researchclaw.pipeline.opencode_bridge.shutil.which",
+            return_value=None,
+        ):
+            cmd = OpenCodeBridge._build_opencode_command(
+                "/usr/bin/opencode", "anthropic/claude-sonnet-4-6", "prompt"
+            )
+        assert cmd == [
+            "/usr/bin/opencode", "run", "-m",
+            "anthropic/claude-sonnet-4-6", "--format", "json", "prompt",
+        ]
+
+    def test_non_linux_does_not_wrap_even_if_script_present(self):
+        """On macOS/BSD, `script` uses a different arg order; never wrap (no regression)."""
+        with patch(
+            "researchclaw.pipeline.opencode_bridge.sys.platform", "darwin"
+        ), patch(
+            "researchclaw.pipeline.opencode_bridge.shutil.which",
+            return_value="/usr/bin/script",
+        ):
+            cmd = OpenCodeBridge._build_opencode_command(
+                "/usr/bin/opencode", "anthropic/claude-sonnet-4-6", "prompt"
+            )
+        assert "script" not in cmd[0]
+        assert cmd[0] == "/usr/bin/opencode"
+
+    def test_prompt_with_shell_metacharacters_is_quoted(self):
+        """The wrapped inner string must shell-quote the prompt so a shell
+        re-parses it back into the exact original argv (no injection)."""
+        import shlex
+
+        payload = "echo 'hi'; rm -rf /"
+        with patch(
+            "researchclaw.pipeline.opencode_bridge.sys.platform", "linux"
+        ), patch(
+            "researchclaw.pipeline.opencode_bridge.shutil.which",
+            return_value="/usr/bin/script",
+        ):
+            cmd = OpenCodeBridge._build_opencode_command("/usr/bin/opencode", "m", payload)
+        inner = cmd[4]
+        # A shell parsing `inner` must recover the original argv verbatim,
+        # with the payload as a single token rather than separate commands.
+        assert shlex.split(inner) == [
+            "/usr/bin/opencode", "run", "-m", "m", "--format", "json", payload,
+        ]
+
+
 # ============================================================
 # TestEnsureMainEntryPoint (BUG-R52-01)
 # ============================================================