Stuck on an issue?

Lightrun Answers was designed to reduce the constant googling that comes with debugging 3rd party libraries. It collects links to all the places you might be looking at while hunting down a tough bug.

And, if you’re still stuck at the end, we’re happy to hop on a call to see how we can help out.

Cannot import blacksheep.contents. Can't deploy on Vercel

See original GitHub issue

Describe the bug I’m trying to replace my FastAPI apps on Vercel with BlackSheep.

Here is an example: https://github.com/clementpoiret/blacksheep-vercel

Unfortunately, it seems I can’t deploy it, it leads to a server error because:

> Ready! Available at http://0.0.0.0:3000
> Building @vercel/python:server/api.py
Installing required dependencies...
> Built @vercel/python:server/api.py [20s]
Traceback (most recent call last):
  File "/home/cp264607/.cache/com.vercel.fun/runtimes/python3/../python/bootstrap.py", line 147, in <module>
    lambda_runtime_main()
  File "/home/cp264607/.cache/com.vercel.fun/runtimes/python3/../python/bootstrap.py", line 127, in lambda_runtime_main
    fn = lambda_runtime_get_handler()
  File "/home/cp264607/.cache/com.vercel.fun/runtimes/python3/../python/bootstrap.py", line 113, in lambda_runtime_get_handler
    mod = importlib.import_module(module_name)
  File "/home/cp264607/anaconda3/lib/python3.8/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1014, in _gcd_import
  File "<frozen importlib._bootstrap>", line 991, in _find_and_load
  File "<frozen importlib._bootstrap>", line 975, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 671, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 783, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/tmp/zeit-fun-b57c65a91f69d/vc__handler__python.py", line 12, in <module>
    __vc_spec.loader.exec_module(__vc_module)
  File "<frozen importlib._bootstrap_external>", line 783, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "./server/api.py", line 1, in <module>
    from blacksheep import Application, Content, Response
  File "/tmp/zeit-fun-b57c65a91f69d/blacksheep/__init__.py", line 7, in <module>
    from .contents import Content as Content
ModuleNotFoundError: No module named 'blacksheep.contents'
TypeError: Object prototype may only be an Object or null: undefined
    at Function.setPrototypeOf (<anonymous>)
    at new LambdaError (/usr/lib/node_modules/vercel/dist/index.js:9679:16)
    at Lambda.<anonymous> (/usr/lib/node_modules/vercel/dist/index.js:9812:27)
    at Generator.next (<anonymous>)
    at fulfilled (/usr/lib/node_modules/vercel/dist/index.js:9726:58)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)

Do you know what is happening? Thanks