relationship between C# compiler and .net core sdk
does a preview version of .net core use a preview version of the compiler? What is the relationship there?
Ryes, the .NET SDK comes with a matching version of the C# compiler, and preview SDKs contain preview compilers
Cso if I have a project that wants to build for .net 6, .net 8, and preview .net 9. it's going to use a GA versoin of the build system for 6 and 8 and the preview for 9?
Cjust making sure it's no tusing the preview of a compiler with the GA sdk for 6 and 8 for my builds
Cmaking them suspect
Rno, by default the highest SDK version installed is used for everything
Ryou can compile .NET 6 and .NET 8 projects using the .NET 9 SDK
Rand it will use the preview version of the compiler, yes
Rto stop this, you can use https://learn.microsoft.com/en-us/dotnet/core/tools/global-json to force a subdirectory to use some previous version of the SDK
Learn how to use the global.json file to set the .NET SDK version when running .NET CLI commands.
Cok. if I have a project that targets net60, net80, and net90 I would want it to use GA build system for net60 and net80 and net9.0
Cdotnet build in a folder with a projecgt with this line
CCassuming we add the .net 9 preview in there as a target too
Cwe want binaries for each target
Cbut all exect the ..net 9 preview need to not use any preview stuff
Csorry if I'm not explaining it right
Rthere is no way to do that
Ri mean. i guess, you can build it twice and change the target frameworks and SDK in between and stich it together manually. but that is quite unpleasant
Chmm ok. that's unfortunate
Ryou can override the compiler version using https://www.nuget.org/packages/Microsoft.Net.Compilers.Toolset
Ryou can add a reference, and
dotnet build will switch to that compiler. the package versions there correspond to visual studio versions, mostly, so 4.9.2 would correspond to the compiler in VS 17.9, and that is not previewCok, I'll read up on it
Rof course, the SDK does other things which could in principle be a concern
Cyeah, would only want to use the preview sdk only for a preview build of our product
Ri do not think there is really a huge concern in this scenario
Cyou may be right but if certainty is required
Tthen make a dedicated CI job that create the
global.json for thatTdotnet new globaljson <tons of args> --forceTit will override the content of the
global.json only during that runCOk interesting
Tso you scope that to only that dedicated job
TI sincerly suggest to keep on using the same sdk everywhere (outside of preview question)
Tbecause at least you'll get a smooth and consistent dev UX
Talso that will avoid onboarding of new member
T"you have to install sdk 1 2 3 4 5 6 perview 10"
Tnote that the global JSON have flags in it BTW
Twhich allow rollforward
Tso you can tell it that you want 8.0.200 + allowRollforward: major + allow preview
Twhich mean that anything bellow 8.0.200 won't work
T8.0.300 will work
T9.x preview will work
Twhich leaves you with your yaml pipeline now
Tand you just have to change the
install dotnet from sdk to explicitly install a speciifc 9.x-previewTand it will works for all dev / all jobs with 0 change
Tnot even requiring to edit the global.json
TTthis is what I use on the repo i have currently open
Tand the azure pipeline just does:
TTwith 0 args to that step it will literally install THAT version
Tyou can add extra args to
UseDotNet@2 to install a specific 9.x preview