Azure App Service Linux runtime failed on an automatic app restart and failed (panic).

Question

Azure App Service Linux runtime failed on an automatic app restart and failed (panic).

BRUCE AIESI 5

Explain:

Azure App Service Linux runtime failed on an automatic app restart and failed (panic). Remote build produces output.tar.zst but runtime startup expects output.tar.gz and crashes on restart. App was forced to be down until i manually redeployed app from vscode source to clear up.

Include:

Azure App Service Linux runtime.

Your App Service stack (Python 3.10 Linux)

Oryx version from startup logs:

Oryx Version: 0.2.20251017.2

The exact startup error:

panic: Could not find file '/home/site/wwwroot/output.tar.gz'

The contents of /home/site/wwwroot:

output.tar.zst exists

output.tar.gz does NOT exist

Azure App Service Linux runtime.

Connected!

2026-02-11T16:18:01.3524448Z _____

2026-02-11T16:18:01.3525025Z / _ \ __________ _________ ____

2026-02-11T16:18:01.3525054Z / /\ \__ / | _ __ _/ __ \

2026-02-11T16:18:01.3525077Z / | / /| | /| | /\ ___/

2026-02-11T16:18:01.352509Z _| /_____ _/ || ___ >

2026-02-11T16:18:01.3525188Z / / /

2026-02-11T16:18:01.3525202Z A P P S E R V I C E O N L I N U X

2026-02-11T16:18:01.3525215Z

2026-02-11T16:18:01.3525229Z Documentation : http://aka.ms/webapp-linux

2026-02-11T16:18:01.3525242Z Python quickstart: https://aka.ms/python-qs

2026-02-11T16:18:01.3525255Z Python version : 3.10.19

2026-02-11T16:18:01.3525267Z Instance Name : ln1sdlwk00066M

2026-02-11T16:18:01.3525282Z Instance Id : 5d81906d03acb6cf663ab5247e8848ee8b66fdc29baa7df844110e5d392215e8

2026-02-11T16:18:01.3525293Z

2026-02-11T16:18:01.3525307Z Note: Any data outside '/home' is not persisted

2026-02-11T16:18:01.8278155Z Starting OpenBSD Secure Shell server: sshd.

2026-02-11T16:18:01.8331849Z WEBSITES_INCLUDE_CLOUD_CERTS is not set to true.

2026-02-11T16:18:01.8760298Z Updating certificates in /etc/ssl/certs...

2026-02-11T16:18:08.3973778Z rehash: warning: skipping duplicate certificate in azl_SSL.com_TLS_RSA_Root_CA_2022.pem

2026-02-11T16:18:08.4035369Z rehash: warning: skipping duplicate certificate in azl_Sectigo_Public_Server_Authentication_Root_R46.pem

2026-02-11T16:18:08.4092296Z rehash: warning: skipping duplicate certificate in azl_Sectigo_Public_Server_Authentication_Root_E46.pem

2026-02-11T16:18:08.4119808Z rehash: warning: skipping duplicate certificate in azl_SSL.com_TLS_ECC_Root_CA_2022.pem

2026-02-11T16:18:08.4230614Z 4 added, 0 removed; done.

2026-02-11T16:18:08.4231084Z Running hooks in /etc/ca-certificates/update.d...

2026-02-11T16:18:08.425679Z done.

2026-02-11T16:18:08.4299626Z CA certificates copied and updated successfully.

2026-02-11T16:18:08.4646276Z Site's appCommandLine: startuplyophlab.sh

2026-02-11T16:18:08.5496263Z Starting periodic command scheduler: cron.

2026-02-11T16:18:08.550664Z Launching oryx with: create-script -appPath /home/site/wwwroot -output /opt/startup/startup.sh -virtualEnvName antenv -defaultApp /opt/defaultsite -userStartupCommand 'startuplyophlab.sh'

2026-02-11T16:18:08.5658259Z Found build manifest file at '/home/site/wwwroot/oryx-manifest.toml'. Deserializing it...

2026-02-11T16:18:08.5706592Z Build Operation ID: 8234ead6b17cc2e1

2026-02-11T16:18:08.5725996Z Oryx Version: 0.2.20251017.2, Commit: 482d4c55e818733ab33b9d2131f9dc485a21fd03, ReleaseTagName: 20251017.2

2026-02-11T16:18:08.5729345Z Output is compressed. Extracting it...

2026-02-11T16:18:08.6772115Z panic: Could not find file '/home/site/wwwroot/output.tar.gz'.

2026-02-11T16:18:08.677285Z

2026-02-11T16:18:08.6772893Z goroutine 1 [running]:

2026-02-11T16:18:08.6773047Z common.ExtractTarball({0xc00001caa0, 0x20}, {0xc00017a0bb, 0x14})

2026-02-11T16:18:08.6773074Z /usr/local/go/src/common/compressionHelper.go:29 +0x339

2026-02-11T16:18:08.6773094Z main.(*PythonStartupScriptGenerator).GenerateEntrypointScript(0xc00012f898)

2026-02-11T16:18:08.6773114Z /go/src/python/scriptgenerator.go:68 +0x26c

2026-02-11T16:18:08.677314Z main.main()

2026-02-11T16:18:08.6773159Z /go/src/python/main.go:89 +0xa05

2026-02-11T16:18:08.6836953Z chmod: cannot access '/opt/startup/startup.sh': No such file or directory

2026-02-11T16:18:08.6856686Z /opt/startup/init_container.sh: line 90: /opt/startup/startup.sh: No such file or directory

3 answers

Your answer

Answer 1

Golla Venkata Pavani 2,340 Microsoft External Staff Moderator

Hi @BRUCE AIESI ,

Thank you for reaching us regarding the issue and providing logs where the Azure App Service on Linux cannot find the output.tar.gz file during an automatic app restart, leading to a panic error. Yes you're right and thank you for identifying the root cause. You are hitting a known (and temporary) mismatch between a recent Oryx release (0.2.20251017.2) and the Python runtime container on Azure App Service Linux.

During a remote build the platform now compresses the built artifacts (including your antenv virtual environment) as output.tar.zst, but the container startup script is still hardcoded to look for the older output.tar.gz. When the app restarts automatically, it panics because the expected .gz file is missing.
That’s exactly why a fresh redeploy from VS Code fixed it, triggered a clean remote build that produced a consistent set of files.

https://learn.microsoft.com/en-us/azure/app-service/deploy-zip?tabs=cli

Kindly let us know if the above helps or you need further assistance on this issue.

Please "accept" if the information helped you. This will help us and others in the community as well.

BRUCE AIESI 5 Reputation points

2026-02-18T19:52:47.61+00:00

I have ten production Azure Web Apps running on Python 3.10. During a restart, which version of the Oryx release will they use—specifically, will it use version 0.2.20251017.2? Or has the fix already been implemented so that a newer Oryx release will resolve the issue? Please advise. Thank you.
BRUCE AIESI 5 Reputation points

2026-02-18T19:53:21.81+00:00

I have ten production Azure Web Apps running on Python 3.10. During a restart, which version of the Oryx release will they use—specifically, will it use version 0.2.20251017.2? Or has the fix already been implemented so that a newer Oryx release will resolve the issue? Please advise. Thank you.
Golla Venkata Pavani 2,340 Reputation points Microsoft External Staff Moderator

2026-02-20T20:46:10.5933333+00:00
Hi @BRUCE AIESI ,

Thanks for the posting you query.

During an automatic restart, Azure App Service Linux uses the Oryx version bundled in the runtime image, not a new or updated one.

For Python 3.10 Linux apps, this is still Oryx 0.2.20251017.2 in affected environments.

There is no public confirmation yet that a newer Oryx version with the fix has been rolled out to App Service Linux runtimes.

Until the platform image is updated, the same issue can still occur on restarts, even without new deployments.

Reference:
https://learn.microsoft.com/azure/app-service/configure-language-python

Kindly let us know if the above helps or you need further assistance on this issue.

Please "upvote" if the information helped you. This will help us and others in the community as well.
Golla Venkata Pavani 2,340 Reputation points Microsoft External Staff Moderator

2026-02-23T18:17:38.3266667+00:00

Hi @BRUCE AIESI ,

I'm just reaching out to see if your issue has been resolved or if you've had a chance to review my previous comment?

Answer 2

BRUCE AIESI 5

Issue on the Azure us of the Oryx GitHub Repo (Public)

If the problem is:

Oryx build produces output.tar.zst

App Service runtime startup expects output.tar.gz

And they don’t align, so thats an Oryx/platform mismatch.

Answer 3

The issue you are experiencing with the Azure App Service Linux runtime appears to be related to the expected output file format during the app startup process. The error message indicates that the runtime is looking for a file named output.tar.gz, but only output.tar.zst exists in the /home/site/wwwroot directory. This discrepancy leads to a panic and causes the app to fail on restart.

Key Points:

Runtime Environment: You are using the Azure App Service with a Linux stack configured for Python 3.10.
Oryx Version: The Oryx version from your logs is 0.2.20251017.2, which is responsible for the build and startup process of your application.
Startup Error: The specific error is panic: Could not find file '/home/site/wwwroot/output.tar.gz', which indicates that the expected file for the startup process is missing.

Suggested Actions:

Check Build Process: Ensure that your build process is correctly generating the output.tar.gz file. You may need to review your deployment scripts or configurations to confirm that the correct output format is being produced.
Manual Redeployment: As you mentioned, manually redeploying the app from VSCode resolved the issue temporarily. This suggests that the deployment process may need to be adjusted to consistently produce the required file format.
Review Deployment Logs: Check the deployment logs for any errors or warnings that could indicate why the output.tar.gz file was not created. This can provide insights into potential issues during the build phase.

By addressing the output file format and ensuring that the deployment process is correctly configured, you should be able to resolve the startup issues with your Azure App Service application.

References:

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Azure App Service Linux runtime failed on an automatic app restart and failed (panic).

3 answers

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