aria2 install path: bare 'import manager_core' → ModuleNotFoundError on the pip package (every install-model fails when COMFYUI_MANAGER_ARIA2_SERVER is set)

[artokun]

Summary

In the pip-packaged comfyui-manager (installed via pip install comfyui-manager, used with --enable-manager), every model install fails with ModuleNotFoundError: No module named 'manager_core' when COMFYUI_MANAGER_ARIA2_SERVER is set. This makes the built-in aria2 fast-download path completely unusable for pip-package users.

Version

comfyui-manager==4.2.2 (pip), ComfyUI 0.27.0, Python 3.12, Linux.

Root cause

comfyui_manager/common/manager_downloader.py, aria2_download_url():

def aria2_download_url(model_url: str, model_dir: str, filename: str):
    import manager_core as core            # <-- line 79
    ...
    if model_dir.startswith(core.comfy_path):
        model_dir = model_dir[len(core.comfy_path):]

import manager_core is a flat/top-level import that only resolves in the legacy custom_nodes/ComfyUI-Manager/ layout (where manager_core.py sits on sys.path). In the pip package the module is comfyui_manager.glob.manager_core, so the bare import manager_core raises ModuleNotFoundError.

The function is only reached when COMFYUI_MANAGER_ARIA2_SERVER is set (see download_url() → if aria2: return aria2_download_url(...)), so pip users without aria2 never hit it — but anyone enabling the aria2 RPC path (the documented fast-download feature) has every install-model task fail instantly.

Reproduce

1. pip install comfyui-manager, launch ComfyUI with --enable-manager.
2. Run an aria2c --enable-rpc daemon; set COMFYUI_MANAGER_ARIA2_SERVER=http://127.0.0.1:6800 (+ secret) in ComfyUI's env.
3. Queue any model install (UI or POST /v2/manager/queue/task kind install-model).
4. Task status → error; server log: [ComfyUI-Manager] ERROR: No module named 'manager_core'. Nothing downloads.

Suggested fix

Import via the package path with a fallback for the legacy layout:

try:
    from comfyui_manager.glob import manager_core as core
except ImportError:                     # legacy custom_nodes layout
    import manager_core as core

(Same pattern likely needed anywhere else in the aria2 path that does a bare import manager_core / import manager_util.)

Workaround (for others hitting this)

Drop a shim manager_core.py on sys.path exposing comfy_path (a string pointing at the ComfyUI root) — the only attribute aria2_download_url consumes. Because the import is function-level, writing the shim takes effect without restarting ComfyUI.

[artokun]

Additional finding: the aria2 path also breaks custom-node (CNR) installs, not just models — and importantly, the obvious fix for the missing import (from comfyui_manager.glob import manager_core) would not be sufficient on its own.

cnr_install (manager_core.py ~L1308) downloads CNR_temp_*.zip into get_default_custom_nodes_path() (= <comfy_root>/custom_nodes) via manager_downloader.download_url, then unzips from that same absolute path. When download_url routes to aria2_download_url, the path relativization

if model_dir.startswith(core.comfy_path):
    model_dir = model_dir[len(core.comfy_path):]      # <root>/custom_nodes -> /custom_nodes
download_dir = model_dir if model_dir.startswith('/') else os.path.join('/models', model_dir)

strips the root, so aria2 is told to write to a top-level /custom_nodes while extract_package_as_zip reads from <root>/custom_nodes → FileNotFoundError → empty node dir. (Models avoid this only when the model root isn't under comfy_path.)

The relativization is clearly model-centric (the /models join is the tell) and mishandles any download target under the ComfyUI root. So restoring the real comfy_path via the import fix reintroduces this for CNR installs. A complete fix should make aria2_download_url pass the caller's absolute model_dir through unchanged (aria2 runs in the same container, so absolute paths are correct as-is) rather than stripping-and-re-rooting under /models.