As part of our build process we package and push a set of nuget packages to our artifacts repository. Recently we made the switch to Azure Artifacts after which uploading packages started to fail with the following error message:
The nuget command failed with exit code(1) and error(Response status code does not indicate success: 409 (Conflict - The feed already contains ‘ExceptionHandling.Database 6.4.1'. (DevOps Activity ID: CAEC4462-2E20-4C69-9AFE-3BBC3C961E20)).)
Packages failed to publish
Ok, it seems that Azure Artifacts doesn’t like it when you try to upload the same packages multiple times. (We bumped the package version manually and didn’t care about overwriting an existing package so far). Can we fix this?
We are using the NuGet task. This task has an interesting option: ‘Allow duplicates to be skipped’. Let’s try this…
Unfortunately we ended up with the same error message as above. Let’s take a look at the documentation:
If you continually publish a set of packages and only change the version number of the subset of packages that changed, use this option. It allows the task to report success even if some of your packages are rejected with 409 Conflict errors.
This option is currently only available on Azure Pipelines and using Windows agents. If NuGet.exe encounters a conflict, the task will fail.
Aha, the last line explains everything. We are using Azure DevOps Server and it seems that this option only works in the cloud(no idea why?).
As a workaround I switched to a commandline task and invoked nuget.exe directly. If you are using a recent nuget.exe version you can add the –skipduplicate option to skip existing packages.
