This is co-released with core framework release v2
Users have reported sporadic problems restoring the version 1.2.0 NuGet packages. This is a result of .NET Foundation's
code signing system changing the default time stamp server from DigiCert to Microsoft, which is not supported on .NET SDK
6.0.3xx (which is associated with Visual Studio 2022 LTS release 17.2). Users who were trying to stick with purely LTS
builds of tools experienced NU3003
("The package signature is invalid or cannot be verified on this platform."). We have manually reverted back to the
DigiCert time stamp service, which will allow users relying on LTS tooling to be able to restore our packages again.
At this point in time, it is unclear whether this will be fixable for .NET SDK 6.0.3xx or not (and whether the proposed fix in this issue will actually work on all OSes or just Windows). Regardless of whether this change is applied or not, it is our intention to permanently stick with the DigiCert time stamp service because it provides maximum compatibility with currently shipping versions of the SDK.
[Theory]. Since third party libraries may allow other returned types, they will no longer
trigger this warning. (Third party extensions which provide their own analyzers should consider having
a similar rule if you change the valid return types for test methods, including the case where you
FactAttribute overrides but still have the same return type limitations.)