{"record":{"id":"b51cafdb2426dc88","repo":"Aider-AI/aider","slug":"empty-patch-section-found","errorCode":null,"errorMessage":"Empty patch section found.","messagePattern":"Empty patch section found\\.","errorType":"exception","errorClass":"DiffError","httpStatus":null,"severity":"error","filePath":"aider/coders/patch_coder.py","lineNumber":189,"sourceCode":"\n    # Finalize any pending chunk at the end of the section\n    if del_lines or ins_lines:\n        chunks.append(\n            Chunk(\n                orig_index=len(context_lines) - len(del_lines),\n                del_lines=del_lines,\n                ins_lines=ins_lines,\n            )\n        )\n\n    # Check for EOF marker\n    is_eof = False\n    if index < len(lines) and _norm(lines[index]) == \"*** End of File\":\n        index += 1\n        is_eof = True\n\n    if index == start_index and not is_eof:  # Should not happen if patch is well-formed\n        raise DiffError(\"Empty patch section found.\")\n\n    return context_lines, chunks, index, is_eof\n\n\ndef identify_files_needed(text: str) -> List[str]:\n    \"\"\"Extracts file paths from Update and Delete actions.\"\"\"\n    lines = text.splitlines()\n    paths = set()\n    for line in lines:\n        norm_line = _norm(line)\n        if norm_line.startswith(\"*** Update File: \"):\n            paths.add(norm_line[len(\"*** Update File: \") :].strip())\n        elif norm_line.startswith(\"*** Delete File: \"):\n            paths.add(norm_line[len(\"*** Delete File: \") :].strip())\n    return list(paths)\n\n\n# --------------------------------------------------------------------------- #","sourceCodeStart":171,"sourceCodeEnd":207,"githubUrl":"https://github.com/Aider-AI/aider/blob/5dc9490bb35f9729ef2c95d00a19ccd30c26339c/aider/coders/patch_coder.py#L171-L207","documentation":"Raised by PatchCoder when an update-file section consumed zero body lines and no '*** End of File' marker was present (index == start_index and not is_eof). The parser expects at least one patch line, chunk, or the EOF marker between section headers.","triggerScenarios":"A '*** Update File: path' header immediately followed by another header or '*** End Patch' with no +/-/space lines in between; or two consecutive section markers with an empty body.","commonSituations":"Model emits an update header then forgets the hunk; degenerate/m truncated patches; placeholders like '*** Update File: foo.py' with the body accidentally stripped.","solutions":["Provide at least one context/added/deleted line after every '*** Update File:' header, or drop the empty section entirely.","Check for truncation if the patch ends abruptly — increase output limits.","Retry the model with the error message so it re-emits complete sections.","If the intent was a no-op update, remove the header rather than leaving an empty section."],"exampleFix":"# before\n*** Update File: foo.py\n*** End Patch\n\n# after\n*** Update File: foo.py\n@@\n context line\n-old line\n+new line\n*** End Patch","handlingStrategy":"validation","validationCode":"def empty_update_sections(patch_text: str) -> list[str]:\n    lines = patch_text.splitlines()\n    empty, i = [], 0\n    while i < len(lines):\n        if lines[i].strip().startswith(\"*** Update File:\"):\n            j, body = i + 1, 0\n            while j < len(lines) and not lines[j].strip().startswith(\"***\"):\n                if lines[j].strip():\n                    body += 1\n                j += 1\n            if body == 0:\n                empty.append(lines[i])\n            i = j\n        else:\n            i += 1\n    return empty  # non-empty → drop these sections before parsing","typeGuard":null,"tryCatchPattern":"try:\n    coder.get_edits(patch_text)\nexcept ValueError as e:\n    if \"Empty patch section\" in str(e):\n        patch_text = drop_or_fill_empty_sections(patch_text)\n        coder.get_edits(patch_text)\n    else:\n        raise","preventionTips":["Strip placeholder '*** Update File:' headers with no hunks before parsing.","Check for truncated patches (no '*** End Patch' tail) — truncation often yields empty sections.","Feed the error back so the model re-emits complete sections."],"tags":["aider","patch-format","apply-patch","parsing"],"backgroundTag":null,"analyzedSha":"5dc9490bb35f9729ef2c95d00a19ccd30c26339c","analyzedAt":"2026-08-15T05:40:10.498Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}