{"record":{"id":"6172fb863a947a50","repo":"sgl-project/sglang","slug":"could-not-import-any-module-prefix-of-qualified","errorCode":null,"errorMessage":"could not import any module prefix of '{qualified_name}'","messagePattern":"could not import any module prefix of '(.+?)'","errorType":"exception","errorClass":"ImportError","httpStatus":null,"severity":"error","filePath":"python/sglang/srt/debug_utils/source_patcher/code_patcher.py","lineNumber":183,"sourceCode":"def _resolve_target(qualified_name: str) -> Callable[..., Any]:\n    \"\"\"Resolve 'pkg.mod.Class.method' to the actual function object.\n\n    Tries progressively shorter module paths from right to left,\n    then uses getattr for the remaining attribute chain.\n    \"\"\"\n    parts: list[str] = qualified_name.split(\".\")\n\n    target: Any = None\n    for split_idx in range(len(parts), 0, -1):\n        module_path: str = \".\".join(parts[:split_idx])\n        try:\n            target = importlib.import_module(module_path)\n            attr_parts: list[str] = parts[split_idx:]\n            break\n        except ImportError:\n            continue\n    else:\n        raise ImportError(f\"could not import any module prefix of '{qualified_name}'\")\n\n    for attr_name in attr_parts:\n        target = getattr(target, attr_name)\n\n    if isinstance(target, classmethod):\n        target = target.__func__\n    if not callable(target):\n        raise TypeError(\n            f\"resolved target '{qualified_name}' is not callable: {type(target)}\"\n        )\n\n    return target\n","sourceCodeStart":165,"sourceCodeEnd":196,"githubUrl":"https://github.com/sgl-project/sglang/blob/0132848349585cfe6aae51c4941cbae872505f8a/python/sglang/srt/debug_utils/source_patcher/code_patcher.py#L165-L196","documentation":"Raised by source_patcher's _resolve_target when it cannot importlib.import_module any dotted prefix of the qualified name. The resolver walks candidate split points (to handle module attrs like pkg.mod.Class.method) and only raises if every prefix import fails. This means the module itself is missing — not the attribute (a missing attr would raise AttributeError instead).","triggerScenarios":"Specifying a patch target like 'sglang.srt.nonexistent.module.fn' where no importable module exists at any prefix; also for a name with no dots at all, since a top-level module import is still attempted. Triggered via _apply_specs or in tests like test_resolve_nonexistent_raises.","commonSituations":"Renamed/moved modules after an sglang upgrade while patch YAML still references old paths; typos in patch spec files; circular-import or import-time errors inside the target module that surface as ImportError; missing optional dependency guarded imports.","solutions":["Verify the module path: run python -c \"import pkg.module\" and fix the path in the patch spec","If the import fails due to an error inside the module (not ModuleNotFoundError), fix that underlying import error first","Regenerate or update patch YAML files after upgrading sglang so targets match the new module layout","If the symbol moved, grep for it in the new version and update the qualified name"],"exampleFix":"# before\nspec = PatchSpec(target='sglang.srt.layers.old_path.fn', ...)\n\n# after\nspec = PatchSpec(target='sglang.srt.layers.new_path.fn', ...)","handlingStrategy":"validation","validationCode":"import importlib\nparts = qualified_name.split('.')\nif not any(_try_import('.'.join(parts[:i])) for i in range(1, len(parts) + 1)):\n    raise ConfigError(f'no importable module prefix for {qualified_name}')\n\ndef _try_import(mod):\n    try:\n        importlib.import_module(mod); return True\n    except ImportError:\n        return False","typeGuard":"def resolves_to_module_prefix(qualified_name: str) -> bool:\n    import importlib\n    parts = qualified_name.split('.')\n    return any(\n        (lambda m: _import_ok(m))('.'.join(parts[:i]))\n        for i in range(1, len(parts) + 1)\n    ) if parts else False\n\ndef _import_ok(mod):\n    import importlib\n    try:\n        importlib.import_module(mod); return True\n    except ImportError:\n        return False","tryCatchPattern":"try:\n    target = _resolve_target(qualified_name)\nexcept ImportError:\n    log.error('module for %s not found — was it renamed?', qualified_name)\n    raise","preventionTips":["Pin sglang version when using source patches","Verify 'import pkg.module' works in the runtime env before applying patches","Regenerate patch specs after upgrades that move modules"],"tags":["import","patching","source-patcher","sglang"],"backgroundTag":"module-not-found","analyzedSha":"0132848349585cfe6aae51c4941cbae872505f8a","analyzedAt":"2026-08-28T05:10:05.995Z","schemaVersion":2},"datasetVersion":"2026-08-28T06:17:29.519Z"}