How do I resolve "No module named 'frontend'" error message on Google Cloud Function

Question

I'm trying to deploy a cloud function with Python 3.9 but when I run

gcloud functions deploy my_function --project my_project --runtime python39 --trigger-resource bucket_name --trigger-event google.storage.object.finalize

the deploy fails with this error:

Traceback (most recent call last):
  File "/layers/google.python.pip/pip/bin/functions-framework", line 8, in <module>
    sys.exit(_cli())
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/click/core.py", line 1128, in __call__
    return self.main(*args, **kwargs)
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/click/core.py", line 1053, in main
    rv = self.invoke(ctx)
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/click/core.py", line 1395, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/click/core.py", line 754, in invoke
    return __callback(*args, **kwargs)
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/functions_framework/_cli.py", line 37, in _cli
    app = create_app(target, source, signature_type)
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/functions_framework/__init__.py", line 288, in create_app
    spec.loader.exec_module(source_module)
  File "<frozen importlib._bootstrap_external>", line 843, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/workspace/main.py", line 2, in <module>
    import fitz
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/fitz/__init__.py", line 1, in <module>
    from frontend import *
ModuleNotFoundError: No module named 'frontend'

I found a similar problem here but how can i install PyMuPDF in the cloud function? Shouldn't it install it by itself via the requirements.txt file?

Here's my directory structure:

── folder
   ├── main.py
   ├── requirements.txt

Here's my main.py :

import numpy as np
import fitz
import os
from google.cloud import storage

def my_function()
    do stuff with fitz

Here's my requirements.txt file:

 cachetools==4.2.4 certifi==2021.10.8 charset-normalizer==2.0.9 ci-info==0.2.0 click==8.0.3 configobj==5.0.6 configparser==5.2.0 etelemetry==0.2.2 filelock==3.4.0 fitz==0.0.1.dev2 future==0.18.2 google-api-core==2.3.0 google-auth==2.3.3 google-cloud-core==2.2.1 google-cloud-storage==1.43.0 google-crc32c==1.3.0 google-resumable-media==2.1.0 googleapis-common-protos==1.54.0 httplib2==0.20.2 idna==3.3 isodate==0.6.0 lxml==4.6.4 networkx==2.6.3 nibabel==3.2.1 nipype==1.7.0 numpy==1.21.4 packaging==21.3 pandas==1.3.4 pathlib==1.0.1 protobuf==3.19.1 prov==2.0.0 pyasn1==0.4.8 pyasn1-modules==0.2.8 pydot==1.4.2 PyMuPDF==1.19.2 pyparsing==3.0.6 python-dateutil==2.8.2 pytz==2021.3 pyxnat==1.4 rdflib==6.0.2 requests==2.26.0 rsa==4.8 scipy==1.7.3 simplejson==3.17.6 six==1.16.0 traits==6.3.2 urllib3==1.26.7 joblib~=1.1.0

I created this list through pip freeze> requirements.txt

Answer 1

In the thread you linked, there are several solutions, and an interesting one seems to be that a package named fitz conflicts with PyMuPDF , as they both use the same top name inside a script (being fitz ). I see both libraries are in your requirements.txt , so this could be the cause of this error. I tested adding both libraries inside a Cloud Function and received the same error, which was resolved after removing fitz 0.0.1.dev2 from the file, and using only PyMuPDF .

You can see another example of this behavior from this GitHub issue.