loop-benchmarking

commit 69173d2750e5cab2d6a94d1c152116be336341c2
parent 77e7e9a06140edc233811dccc1cb005b0402575d
Author: Brian Graham <brian@buildingbetterteams.de>
Date:   Wed,  8 Apr 2026 09:21:29 +0200

Fix large prompt handling: use wrapper script instead of bash -c

bash -c with $(cat) broke on quotes in settings JSON.
Now writes a shell wrapper script that reads the prompt from file.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Diffstat:
M
harness/run.py
 | 
13
++++++++-----

1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/harness/run.py b/harness/run.py
@@ -270,12 +270,15 @@ def invoke_claude(cell: dict, workspace: Path, run_dir: Path, project_dir: Path,
         if ctx_file.exists():
             cmd_base.extend(["--append-system-prompt", ctx_file.read_text()])
 
-    # Build final command: for large prompts, use shell to read from file
+    # Build final command: for large prompts, write a shell wrapper script
     if prompt_file:
-        # Use shell to cat the prompt file into -p to avoid arg list limit
-        cmd_str = " ".join(shlex.quote(c) for c in cmd_base)
-        cmd = ["bash", "-c", f'{cmd_str} -p "$(cat {shlex.quote(str(prompt_file))})"']
-        use_shell = False  # already wrapped in bash -c
+        wrapper = Path(tempfile.mktemp(suffix=".sh", prefix="run-claude-"))
+        wrapper_lines = ["#!/bin/bash"]
+        wrapper_lines.append(f'PROMPT=$(cat {shlex.quote(str(prompt_file))})')
+        wrapper_lines.append(" ".join(shlex.quote(c) for c in cmd_base) + ' -p "$PROMPT"')
+        wrapper.write_text("\n".join(wrapper_lines))
+        wrapper.chmod(0o755)
+        cmd = ["bash", str(wrapper)]
     else:
         cmd = [*cmd_base, "-p", prompt]