Getting version `GLIBC_2.33' not found on http triggered function

Question

Getting version `GLIBC_2.33' not found on http triggered function. I have seen the below as an issue detected by Azure. I have tried setting ubuntu-latest back to 20.04 and the deployment pipeline fails with the error "##[error]No config name or imagelabel provided in request". Deploying with ubuntu-latest works fine but then I get the GLIBC message. I tried adding "cryptography==43.0.3" to my requirements.txt but that still results in the GLIBC message. This is on the member-risk-score-monitoring-ui-rest-api function app, "navigation" function.

Here's the Azure warning:**

Action recommended: Possible issue detected for your function app**

Current state	Active
Current state	Active
Created at	5/20/2025 9:00:43 PM UTC
Description	You are receiving this email because you have been identified as a customer using Azure Functions who may encounter issues with Python functions that utilize the azure-identity or cryptography modules. These problems, such as missing functions or "module not found" errors, have been affecting customers who released or updated their Function App code after November 27th, 6 PM UTC, due to recent changes in the cryptography module by its maintainers.Recommended actionTo resolve this issue, please consider one of the following workarounds:Retry performing the deployment using the Remote Build: https://learn.microsoft.com/en-us/azure/azure-functions/functions-deployment-technologies?tabs=windows#remote-buildIn case you are using Azure Pipelines please change the vmImageName tag from “ubuntu-latest” to “ubuntu-20.04” for your yaml file- please refer to https://learn.microsoft.com/en-us/azure/devops/pipelines/agents/hosted?view=azure-devops&tabs=yaml#softwarePin the cryptography module to the previous version (cryptography==43.0.3 ) in your requirements.txt file. After making this change, redeploy your Azure Function. For more details, refer to https://github.com/Azure/azure-sdk-for-python/issues/38725More informationIf you have questions, get answers from community experts in Microsoft Q&A. If you have a support plan and you need technical help, create a support request:Under Issue type, select Technical.Under Subscription, select your subscription.Under Service, click My services, then select Function App.Under Summary, type a description of your issue.Under Problem type, select Application code deployment.Under Problem subtype, select Application issues post deployment.
Solution
Learn More	https://github.com/Azure/azure-sdk-for-python/issues/38725

Answer 1

Hi michael.sweeney,

The error message about GLIBC_2.33 not found occurs because the version of the cryptography Python package (or other related modules like azure-identity) used in your Azure Function requires a newer version of the GNU C Library (glibc) than what is currently available in the Azure Functions Linux runtime environment.

This causes compatibility issues when your function runs, leading to the error you’re seeing.

To resolve this, please try the following steps:

Use Remote Build :

Let Azure build your app’s dependencies in its own environment. This ensures compatibility with the runtime’s system libraries.

Change Your Pipeline Build Agent :

If you use Azure Pipelines, set the build agent image to Ubuntu 20.04 (vmImage: 'ubuntu-20.04') instead of ubuntu-latest. This matches the Azure runtime better and avoids version mismatches.

Pin Cryptography Version :

In your requirements.txt, set cryptography==43.0.3 to use a version compatible with Azure Functions.

Clean Local Builds Before Deploying :

Remove any locally built packages before deploying to avoid shipping incompatible binaries.

To help you better understand, kindly refer to the documentations below:

• Troubleshoot Python errors in Azure Functions (python-mode-configuration)
• Troubleshoot Python errors in Azure Functions (python-mode-decorators)
• Troubleshoot common issues during Azure Runtime upgrade

More detailed guidance can be found in the Azure Functions Deployment Documentation and the GitHub issue you referenced.

https://stackoverflow.com/questions/75146548/version-glibc-2-33-not-found-when-trying-to-open-vscode-from-terminal

After applying these changes, please redeploy your function app. This approach has helped many customers resolve the GLIBC_2.33 error with Python Azure Functions.

Please let me know incase of further queries, I would be happy to assist you.