Shall we deprecate netcoreapp3.1 build?

[pgrawehr]

I was attempting to upgrade a few dependencies (like Microsoft.Extensions.Logging) to V7.0.0, but this causes a lot of warnings of the form

C:\Users\Patrick\.nuget\packages\microsoft.extensions.logging.abstractions\7.0.0\buildTransitive\netcoreapp2.0\Microsof
t.Extensions.Logging.Abstractions.targets(4,5): error : Microsoft.Extensions.Logging.Abstractions 7.0.0 doesn't support
 netcoreapp3.1 and has not been tested with it. Consider upgrading your TargetFramework to net6.0 or later. You may als
o set <SuppressTfmSupportBuildWarnings>true</SuppressTfmSupportBuildWarnings> in the project file to ignore this warnin
g and attempt to run in this unsupported configuration at your own risk. [C:\projects\iot3\src\devices\Nmea0183\tests\N
mea0183.Tests.csproj::TargetFramework=netcoreapp3.1]
C:\Users\Patrick\.nuget\packages\microsoft.extensions.dependencyinjection\7.0.0\buildTransitive\netcoreapp2.0\Microsoft
.Extensions.DependencyInjection.targets(4,5): error : Microsoft.Extensions.DependencyInjection 7.0.0 doesn't support ne
tcoreapp3.1 and has not been tested with it. Consider upgrading your TargetFramework to net6.0 or later. You may also s
et <SuppressTfmSupportBuildWarnings>true</SuppressTfmSupportBuildWarnings> in the project file to ignore this warning a
nd attempt to run in this unsupported configuration at your own risk. [C:\projects\iot3\src\devices\Nmea0183\tests\Nmea
0183.Tests.csproj::TargetFramework=netcoreapp3.1]

We can either:

• Suppress the warning
• make the dependency TFM-dependent
• drop netcoreapp 3.1 support completely

Since we would likely keep netstandard2.0 support, I would suggest the third option. I can't think of a reason why one would create a new project with net3.1, and projects still under development should be easy to upgrade.

[joperezr]

netcoreapp 3.1 goes out of support very soon (December 13th) so I think it is totally fine to drop that asset from our packages and instead just have the new LTS version (net6.0) which we already target. That said, I think dropping a TFM support from the packages should be considered a breaking change that is only done when bumping the major version. I don't see why we can't do it now, but just wanted to mention that this should be planned for 3.0 whenever we are ready to ship that.

[pgrawehr]

I agree to that. But since we intend to do that 3.0 step anyway after the GpioPin change, this would be good to do simultaneously. I have the PR almost ready.

[raffaeler]

+1, next time we should discuss what exactly we want to plan for 3.0, which should happen quite soon.

[Ellerbach]

I have the PR almost ready.

Go for it, fully aligned!