Error when running Python 3.13 Web App: "python: error while loading shared libraries: libpython3.11.so.1.0: cannot open shared object file: No such file or directory"

Question

Error when running Python 3.13 Web App: "python: error while loading shared libraries: libpython3.11.so.1.0: cannot open shared object file: No such file or directory"

Tyler Suard 0

Hello, I am trying to run an Azure WebApp using the python 3.13 stack. However it won't even start up because I am getting this error:

python: error while loading shared libraries: libpython3.11.so.1.0: cannot open shared object file: No such file or directory

Why is it trying to load python 3.11? I am using python 3.13 in my environment, and I built it using Github Actions with python 3.13.

Tyler Suard 0 Reputation points

2025-06-17T23:06:30.1466667+00:00

Complete error:

025-06-17T22:10:00.697867123Z / _ \ __________ _________ ____

2025-06-17T22:10:00.697907859Z / /\ \__ / | _ __ _/ __ \

2025-06-17T22:10:00.697915072Z / | / /| | /| | /\ ___/

2025-06-17T22:10:00.697920733Z _| /_____ _/ || ___ >

2025-06-17T22:10:00.697931363Z / / /

2025-06-17T22:10:00.697936953Z A P P S E R V I C E O N L I N U X

2025-06-17T22:10:00.697942233Z

2025-06-17T22:10:00.697975325Z Documentation: http://aka.ms/webapp-linux

2025-06-17T22:10:00.697982839Z Python 3.13.3

2025-06-17T22:10:00.697988108Z Note: Any data outside '/home' is not persisted

2025-06-17T22:10:03.466335598Z Starting OpenBSD Secure Shell server: sshd.

2025-06-17T22:10:03.472704325Z WEBSITES_INCLUDE_CLOUD_CERTS is not set to true.

2025-06-17T22:10:03.490644293Z Updating certificates in /etc/ssl/certs...

2025-06-17T22:10:08.197424266Z rehash: warning: skipping ca-certificates.crt,it does not contain exactly one certificate or CRL

2025-06-17T22:10:08.252303629Z 2 added, 0 removed; done.

2025-06-17T22:10:08.269089732Z Running hooks in /etc/ca-certificates/update.d...

2025-06-17T22:10:08.277808062Z done.

2025-06-17T22:10:08.281784162Z CA certificates copied and updated successfully.

2025-06-17T22:10:09.025000728Z Site's appCommandLine: python app.py

2025-06-17T22:10:09.026970690Z Launching oryx with: create-script -appPath /home/site/wwwroot -output /opt/startup/startup.sh -virtualEnvName antenv -defaultApp /opt/defaultsite -userStartupCommand 'python app.py'

2025-06-17T22:10:09.065361215Z Found build manifest file at '/home/site/wwwroot/oryx-manifest.toml'. Deserializing it...

2025-06-17T22:10:09.071730846Z Build Operation ID: 2d83c9f9680feb72

2025-06-17T22:10:09.073858250Z Oryx Version: 0.2.20250505.1, Commit: bec89959884a7663432d6e3c4d36acc30657cb85, ReleaseTagName: 20250505.1

2025-06-17T22:10:09.074543637Z Output is compressed. Extracting it...

2025-06-17T22:10:09.076186378Z Extracting '/home/site/wwwroot/output.tar.gz' to directory '/tmp/8ddad80cf9812a8'...

2025-06-17T22:10:11.864772266Z App path is set to '/tmp/8ddad80cf9812a8'

2025-06-17T22:10:12.085094783Z Writing output script to '/opt/startup/startup.sh'

2025-06-17T22:10:12.182998057Z Using packages from virtual environment antenv located at /tmp/8ddad80cf9812a8/antenv.

2025-06-17T22:10:12.183023404Z Updated PYTHONPATH to '/opt/startup/app_logs:/tmp/8ddad80cf9812a8/antenv/lib/python3.13/site-packages'

2025-06-17T22:10:12.186734884Z python: error while loading shared libraries: libpython3.11.so.1.0: cannot open shared object file: No such file or directory
Laxman Reddy Revuri 5,220 Reputation points Microsoft External Staff Moderator

2025-06-18T04:17:17.0233333+00:00

Hi @Tyler Suard

The error you're encountering libpython3.11.so.1.0: cannot open shared object file even though you're using Python 3.13 on Azure, is happening because your deployed virtual environment was built with Python 3.11. This means it contains compiled binary dependencies (like .so files) that still reference Python 3.11, which doesn’t exist in the Azure App Service runtime for Python 3.13. The root of the issue is that virtual environments are not portable across Python versions or platforms, and deploying a pre-built venv (like antenv) will often cause these compatibility problems.

Avoid uploading any pre-built virtual environments. Instead, let Azure build the environment using Oryx by deploying only your code and requirements.txt. If you're using GitHub Actions or zip deploy, make sure to delete the venv/ or antenv/ folder before packaging. Let Azure handle dependency installation during deployment based on the selected runtime (Python 3.13).
https://learn.microsoft.com/en-us/azure/app-service/configure-language-python
https://github.com/microsoft/Oryx
Tyler Suard 0 Reputation points

2025-06-18T05:38:46.6333333+00:00

@Laxman Reddy Revuri You have helped me on questions in the past and I appreciated it very much, thank you.

I am building using Github Actions, but I am building using Python 3.13. There is no pre-built venv in my repo. So you are saying that after my artifact has been created, I should delete the venv or antenv folder? Here is my Github Actions yaml, along with my files list:
Tyler Suard 0 Reputation points

2025-06-18T06:37:53.11+00:00

@Laxman Reddy Revuri Thank you for your help. When I connected my web app to the repo using the deployment center in my web app, azure created this .yaml for me. I have not changed it. Are you saying that Azure's yaml is wrong?
Laxman Reddy Revuri 5,220 Reputation points Microsoft External Staff Moderator

2025-06-18T07:11:08.2266667+00:00
Hi @Tyler Suard
Yes, Ensure that you are not deploying any pre-built virtual environments. Azure’s App Service uses Oryx to build the environment based on your code and requirements.txt, so the virtual environment must be built fresh on Azure during the deployment process.

Given that you're using GitHub Actions, you should modify your YAML configuration. After creating your virtual environment and before packaging for deployment, ensure to delete the venv/ or antenv/ directories to prevent including those in your deployment artifact.

For example, in your GitHub Actions YAML, you might want to add something like this after the build step

- name: Clean up virtual environment run: | rm -rf venv/
Tyler Suard 0 Reputation points

2025-06-19T01:05:13.1133333+00:00

@Laxman Reddy Revuri is there any way we can let Microsoft know that their YAML is wrong? How can we get them to fix this? Did they not even bother to test this feature before shipping it?
Tyler Suard 0 Reputation points

2025-06-19T05:05:54.8733333+00:00

@Laxman Reddy Revuri how do I mark your comment as the answer?

1 answer

Your answer

Laxman Reddy Revuri 5,220 Reputation points Microsoft External Staff Moderator

2025-06-18T04:17:17.0233333+00:00

Hi @Tyler Suard

The error you're encountering libpython3.11.so.1.0: cannot open shared object file even though you're using Python 3.13 on Azure, is happening because your deployed virtual environment was built with Python 3.11. This means it contains compiled binary dependencies (like .so files) that still reference Python 3.11, which doesn’t exist in the Azure App Service runtime for Python 3.13. The root of the issue is that virtual environments are not portable across Python versions or platforms, and deploying a pre-built venv (like antenv) will often cause these compatibility problems.

Avoid uploading any pre-built virtual environments. Instead, let Azure build the environment using Oryx by deploying only your code and requirements.txt. If you're using GitHub Actions or zip deploy, make sure to delete the venv/ or antenv/ folder before packaging. Let Azure handle dependency installation during deployment based on the selected runtime (Python 3.13).
https://learn.microsoft.com/en-us/azure/app-service/configure-language-python
https://github.com/microsoft/Oryx
Tyler Suard 0 Reputation points

2025-06-18T05:38:46.6333333+00:00

@Laxman Reddy Revuri You have helped me on questions in the past and I appreciated it very much, thank you.

I am building using Github Actions, but I am building using Python 3.13. There is no pre-built venv in my repo. So you are saying that after my artifact has been created, I should delete the venv or antenv folder? Here is my Github Actions yaml, along with my files list:
Tyler Suard 0 Reputation points

2025-06-18T06:37:53.11+00:00

@Laxman Reddy Revuri Thank you for your help. When I connected my web app to the repo using the deployment center in my web app, azure created this .yaml for me. I have not changed it. Are you saying that Azure's yaml is wrong?
Laxman Reddy Revuri 5,220 Reputation points Microsoft External Staff Moderator

2025-06-18T07:11:08.2266667+00:00

Hi @Tyler Suard
Yes, Ensure that you are not deploying any pre-built virtual environments. Azure’s App Service uses Oryx to build the environment based on your code and requirements.txt, so the virtual environment must be built fresh on Azure during the deployment process.

Given that you're using GitHub Actions, you should modify your YAML configuration. After creating your virtual environment and before packaging for deployment, ensure to delete the venv/ or antenv/ directories to prevent including those in your deployment artifact.

For example, in your GitHub Actions YAML, you might want to add something like this after the build step

- name: Clean up virtual environment run: | rm -rf venv/
Tyler Suard 0 Reputation points

2025-06-19T01:05:13.1133333+00:00

@Laxman Reddy Revuri is there any way we can let Microsoft know that their YAML is wrong? How can we get them to fix this? Did they not even bother to test this feature before shipping it?
Tyler Suard 0 Reputation points

2025-06-19T05:05:54.8733333+00:00

@Laxman Reddy Revuri how do I mark your comment as the answer?

Answer 1

Laxman Reddy Revuri 5,220 Microsoft External Staff Moderator

Hi @Tyler Suard
Apologize for any inconvenience caused on this.

In your current GitHub Actions workflow, you're creating a virtual environment (venv) with:

- name: Create and start virtual environment
  run: |
    python -m venv venv
    source venv/bin/activate

Even though you're using Python 3.13 in the workflow, this local venv is not portable and should not be deployed to Azure App Service. Azure uses its own build system (Oryx) and runtime environment to run your app, and it expects to create its own virtual environment using your requirements.txt.

Do not include the venv/ or antenv/ folder in your deployed code.

Just deploy your code and requirements.txt ,and let Azure handle dependency installation at runtime.

Laxman Reddy Revuri 5,220 Reputation points Microsoft External Staff Moderator

2025-06-19T05:31:01.87+00:00

Hi @Tyler Suard
Please accept as "Yes" if the answer provided is useful , so that you can help others in the community looking for remediation for similar issues.

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Error when running Python 3.13 Web App: "python: error while loading shared libraries: libpython3.11.so.1.0: cannot open shared object file: No such file or directory"

1 answer

Your answer