Aider-AI/aider · error · DiffError

Delete File Error - file not found: {path}

Error message

Delete File Error - file not found: {path}

What it means

Thrown when a '*** Delete File: <path>' targets a path not present in current_files — the files aider has in chat context. The parser validates deletes against known files because it has no other way to confirm the target exists. It prevents deleting files the coder never saw.

Source

Thrown at aider/coders/patch_coder.py:371

                    fuzz_accumulator += fuzz
                continue

            # ---------- DELETE ---------- #
            elif norm_line.startswith("*** Delete File: "):
                path = norm_line[len("*** Delete File: ") :].strip()
                index += 1
                if not path:
                    raise DiffError("Delete File action missing path.")
                existing_action = patch.actions.get(path)
                if existing_action:
                    if existing_action.type == ActionType.DELETE:
                        # Duplicate delete – ignore the extra block
                        self.io.tool_warning(f"Duplicate delete action for file: {path} ignored.")
                        continue
                    else:
                        raise DiffError(f"Conflicting actions for file: {path}")
                if path not in current_files:
                    raise DiffError(
                        f"Delete File Error - file not found: {path}"
                    )  # Check against known files

                patch.actions[path] = PatchAction(type=ActionType.DELETE, path=path)
                continue

            # ---------- ADD ---------- #
            elif norm_line.startswith("*** Add File: "):
                path = norm_line[len("*** Add File: ") :].strip()
                index += 1
                if not path:
                    raise DiffError("Add File action missing path.")
                if path in patch.actions:
                    raise DiffError(f"Duplicate action for file: {path}")
                # Check if file exists in the context provided (should not for Add).
                # Note: We only have needed files, a full check requires FS access.
                # if path in current_files:
                #     raise DiffError(f"Add File Error - file already exists: {path}")

View on GitHub (pinned to 5dc9490bb3)

Solutions

  1. Add the file to the chat (e.g. /add path/to/file) so it appears in current_files, then re-apply the patch
  2. Correct the path in the patch to exactly match the chat file's relative path
  3. If the file genuinely doesn't need to exist in chat, delete it manually with rm/git rm instead of via the patch

Example fix

# before (file not in chat)
*** Delete File: unused.py

# after
/add unused.py
# then re-apply the patch containing:
*** Delete File: unused.py
Defensive patterns

Strategy: validation

Validate before calling

def deletes_in_chat(patch_text: str, chat_files: set[str]) -> list[str]:
    missing = []
    for line in patch_text.splitlines():
        if line.startswith("*** Delete File: "):
            p = line[len("*** Delete File: "):].strip()
            if p not in chat_files:
                missing.append(p)
    return missing  # empty list means safe

Try / catch

try:
    edits = coder.get_edits(reply)
except DiffError as e:
    if "Delete File Error - file not found" in str(e):
        for f in extract_deleted_paths(reply):
            coder.commands.cmd_add(f)  # bring file into chat
        edits = coder.get_edits(reply)
    else:
        raise

Prevention

When it happens

Trigger: Patch deletes a file that was never added to the chat (not in current_files); path casing or spelling differs from the chat file's path; deleting a file the model hallucinated.

Common situations: User asks to delete a file they never /added; model guesses a filename; path normalization mismatches (leading './', different separators) between the patch and the chat file list.

Related errors

AI-assisted analysis of Aider-AI/aider@5dc9490bb3 (2026-08-15). Data as JSON: /api/errors/d12ac0bf040a52f1. Report an issue: GitHub.