dotnet build inside CI container fails with NU3028 and NU3037

[svdHero]

NuGet product used:
dotnet.exe

Product version (as by dotnet --version):
5.0.102 inside container mcr.microsoft.com/dotnet/sdk:5.0

Problem description

We have a Jenkins CI server on Ubuntu Server 20.04 LTS which builds our ASP.NET Web API inside a mcr.microsoft.com/dotnet/sdk:5.0 container. Everything has worked fine until this morning when suddenly the build pipeline fails with hundreds of errors of the kind

/MyWorkspace/MyProject/MyProject.csproj : error NU3028: Package 'Microsoft.AspNetCore.Mvc.NewtonsoftJson 5.0.0' from source 'https://api.nuget.org/v3/index.json': The author primary signature's timestamp found a chain building issue: UntrustedRoot: self signed certificate in certificate chain
/MyWorkspace/MyProject/MyProject.csproj : error NU3037: Package 'Microsoft.AspNetCore.Mvc.NewtonsoftJson 5.0.0' from source 'https://api.nuget.org/v3/index.json': The author primary signature validity period has expired.

What's the problem here? As far as I know we have not changed anything on our CI machine and the build job still pulls the same container image mcr.microsoft.com/dotnet/sdk:5.0 for building as always.

[dasMulli]

Just opened #10491 for that

[svdHero]

@dasMulli Danke schön für den Hinweis. 😉

[svdHero]

Closed as dublicate.