dotnet publish fails with 'Metadata generation failed' sometimes

[chuchuva]

Repro steps

Provide the steps required to reproduce the problem:

dotnet publish C:\temp\OurFunctionApp.csproj -c Release -o C:\temp\output

Expected behavior

It should build without an error.

Actual behavior

OurFunctionApp -> C:\temp\bin\Release\netcoreapp2.1\bin\OurFunctionApp.dll
C:\Users\build-admin\.nuget\packages\microsoft.azure.webjobs.script.extensionsmetadatagenerator\1.0.1\build\Microsoft.Azure.WebJobs.Script.ExtensionsMetadataGenerator.targets(20,5): error : Metadata generation failed. [C:\temp\OurFunctionApp.csproj]

Output of dotnet --version: 2.1.503

This error occurs sporadically on our Jenkins server. I can't reproduce it on my computer. Also, I cannot reproduce it if run this command on the Jenkins server from command line prompt.

Can you help?

[ishepherd]

@paulbatum or colleagues - How should we investigate this error?

[ishepherd]

Also asked in Stack Overflow: https://stackoverflow.com/questions/54660616/dotnet-publish-fails-with-metadata-generation-failed-sometimes

[paulbatum]

Maybe if you amend your command to include verbose output, there will be a clue of what the error is? See the -v option documented here.

[ishepherd]

Hi @paulbatum - It came back today and I captured logs with -v diag
I get 50 MB of junk but it doesn't look like any of it is coming from the Microsoft.Azure.WebJobs.Script.ExtensionsMetadataGenerator.dll.

I notice that most of the extensions.json files do not get created - That's an expected output of this task, I think?

---

Anonymized snippet - Let me know if you want the whole thing privately

04:53:18.465   1:7>Target "_GenerateFunctionsExtensionsMetadataPostBuild: (TargetId:501)" in file "C:\Users\build-admin\.nuget\packages\microsoft.azure.webjobs.script.extensionsmetadatagenerator\1.0.1\build\Microsoft.Azure.WebJobs.Script.ExtensionsMetadataGenerator.targets" from project "<FULL-CSPROJ-PATH>" (target "_PublishBuildAlternative" depends on it):
                   Using "GenerateFunctionsExtensionsMetadata" task from assembly "C:\Users\build-admin\.nuget\packages\microsoft.azure.webjobs.script.extensionsmetadatagenerator\1.0.1\build\..\tools\netstandard2.0\Microsoft.Azure.WebJobs.Script.ExtensionsMetadataGenerator.dll".
                   Task "GenerateFunctionsExtensionsMetadata" (TaskId:285)
                     Task Parameter:SourcePath=<PROJECT-ROOT-DIR>\bin\Release\netcoreapp2.1\bin (TaskId:285)
                     Task Parameter:OutputPath=<PROJECT-ROOT-DIR>\bin\Release\netcoreapp2.1\bin (TaskId:285)
04:53:18.506   1:7>C:\Users\build-admin\.nuget\packages\microsoft.azure.webjobs.script.extensionsmetadatagenerator\1.0.1\build\Microsoft.Azure.WebJobs.Script.ExtensionsMetadataGenerator.targets(20,5): error : Metadata generation failed. [<FULL-CSPROJ-PATH>]
                   Done executing task "GenerateFunctionsExtensionsMetadata" -- FAILED. (TaskId:285)
04:53:18.506   1:7>Done building target "_GenerateFunctionsExtensionsMetadataPostBuild" in project "<CSPROJ-NAME>" -- FAILED.: (TargetId:501)
04:53:18.506   1:7>Done Building Project "<FULL-CSPROJ-PATH>" (Publish target(s)) -- FAILED.

[jonathanantoine]

Same for me I have 3 agents on the same Virtual Machine and sometimes one of them produces this kind of error.

[brettsam]

@ishepherd -- could you try again with our latest sdk package? https://www.nuget.org/packages/Microsoft.NET.Sdk.Functions/1.0.26. Do you get the same thing?

[paulbatum]

@jonathanantoine please let us know if you still see this with version 1.0.26 that Brett mentioned above

[ishepherd]

@ishepherd -- could you try again with our latest sdk package? https://www.nuget.org/packages/Microsoft.NET.Sdk.Functions/1.0.26. Do you get the same thing?

Hi @brettsam @paulbatum, we upgraded a week ago and fine all week - but just now the problem reoccurred and all our builds are broken again.

The snippet I posted (#4055 (comment)) is the same, except:

• microsoft.azure.webjobs.script.extensionsmetadatagenerator version is now 1.0.2 instead of 1.0.1
• (TaskIds/TargetIds are different)

[jonathanantoine]

Hello,

We switched to VS hosted agent and it's working fine now. I don't know if the latest package you mention wouod have fix the issue.