Aider-AI/aider · error · DiffError

UPDATE Error: File does not exist: {action.path}

Error message

UPDATE Error: File does not exist: {action.path}

What it means

Application-time failure: an UPDATE action targets a file that does not exist on disk. Unlike DELETE (which warns and skips), UPDATE is strict — there is nothing to apply chunks against, so it raises and the whole apply is wrapped into a ValueError.

Source

Thrown at aider/coders/patch_coder.py:593

                    path_obj.parent.mkdir(parents=True, exist_ok=True)
                    # Ensure single trailing newline, matching reference behavior
                    content_to_write = action.new_content
                    if not content_to_write.endswith("\n"):
                        content_to_write += "\n"
                    self.io.write_text(full_path, content_to_write)

                elif action.type == ActionType.DELETE:
                    self.io.tool_output(f"Deleting {action.path}")
                    if not path_obj.exists():
                        self.io.tool_warning(
                            f"DELETE Warning: File not found, skipping: {action.path}"
                        )
                    else:
                        path_obj.unlink()

                elif action.type == ActionType.UPDATE:
                    if not path_obj.exists():
                        raise DiffError(f"UPDATE Error: File does not exist: {action.path}")

                    current_content = self.io.read_text(full_path)
                    if current_content is None:
                        # Should have been caught during parsing if file was needed
                        raise DiffError(f"Could not read file for UPDATE: {action.path}")

                    # Apply the update logic using the parsed chunks
                    new_content = self._apply_update(current_content, action, action.path)

                    target_full_path = (
                        self.abs_root_path(action.move_path) if action.move_path else full_path
                    )
                    target_path_obj = pathlib.Path(target_full_path)

                    if action.move_path:
                        self.io.tool_output(
                            f"Updating and moving {action.path} to {action.move_path}"
                        )

View on GitHub (pinned to 5dc9490bb3)

Solutions

1. Restore or recreate the file, or switch to the branch/worktree where it exists
2. Fix the path in the patch to the actual file location
3. If the intent is creating new content, change the action to '*** Add File:'

Example fix

# before
*** Update File: renamed_module.py

# after (file was renamed)
*** Update File: src/renamed_module.py

import os

def update_targets_exist(actions) -> list[str]:
    return [a.path for a in actions
            if a.type.name == "UPDATE" and not os.path.exists(os.path.join(ROOT, a.path))]

try:
    coder.apply_edits(edits)
except ValueError as e:
    if "UPDATE Error: File does not exist" in str(e):
        raise RuntimeError(f"file missing; check branch/worktree: {e}")
    raise

When it happens

Trigger: File was deleted or renamed after the patch was parsed; UPDATE path has a typo/casing mismatch; patch generated against a branch where the file exists but applied in a worktree where it doesn't.

Common situations: git branch/worktree switches mid-session; files removed by another tool; case-sensitive filesystem exposing path casing bugs.

Related errors

• Delete File Error - file not found: {path}
• Could not find scope context:\n{scope_txt}
• Could not read file for UPDATE: {action.path}
• File referenced in patch not found: {rel_path}
• Delete File action missing path.

AI-assisted analysis of Aider-AI/aider@5dc9490bb3 (2026-08-15). Data as JSON: /api/errors/d957b04ccad2c94a. Report an issue: GitHub.