--source-only switch: doc and default behavior

[tmds]

dotnet/installer#18358 is introducing a --source-only switch which:

Make the default non source build and add the "--source-only" switch.

From that description, it seems distro maintainers should be using this new switch when building the vmr.

If this is needed, can we give it some more visibility (like by using it in the vmr README)?

Also, open question: could the default be source build for convenience of the distro maintainers?

cc @mmitche @ViktorHofer @omajid

[ViktorHofer]

Agreed, the VMR README.md needs an update.

• When not building source-only, prep.sh shouldn't be invoked.
• When building source-only, the --source-only switch now needs to be passed in.

Also, open question: could the default be source build for convenience of the distro maintainers?

The VMR is now the combined home for the MSFT and the distro maintainers build of the .NET SDK. We decided that we want the default to be the super-set (the MSFT build today) as that mirrors the defaults when building the individual repositories. The VMR can now also be built on Windows (with the build.cmd script) and we want to avoid having completely different build behaviors between Windows and other platforms.

I think it would be good to pin an issue in https://github.com/dotnet/dotnet and/or https://github.com/dotnet/source-build to announce the CLI changes for build.sh.

cc @MichaelSimons

[tmds]

@ViktorHofer would it make sense to name this new flag sourceBuild/sb like the existing flag we had on the repo build.sh scripts?

And is productBuild|pb the proper name to refer to the MSFT build configuration?

[ViktorHofer]

See https://github.com/dotnet/arcade/blob/main/Documentation/UnifiedBuild/Unified-Build-Controls.md#resource-controls for the full list of controls that we plan to use in the VMR.

The intent behind not using sourceBuild/sb anymore is that with the VMR, most of the code is built from source, even in the MSFT build. The new --source-only / DotNetBuildSourceOnly switch indicates that the build only builds from source without prebuilts.

And is productBuild|pb the proper name to refer to the MSFT build configuration?

The MSFT build itself doesn't have a switch. It's the default when DotNetBuildSourceOnly / --source-only is not true. Note that there's also the OfficialBuilder property which is used by the SDK: https://github.com/dotnet/arcade/blob/main/Documentation/UnifiedBuild/Unified-Build-Controls.md#organizational-controls

[tmds]

The intent behind not using sourceBuild/sb anymore is that with the VMR, most of the code is built from source, even in the MSFT build. The new --source-only / DotNetBuildSourceOnly switch indicates that the build only builds from source without prebuilts.

fwiw, I like the name sourceBuild/sb better than --source-only, and I assume the former is going to stay on the repo build scripts?
And, if I had to suggest an alternative: --build-from-source.

The property of the MSFT build is that it does some things which are not source-build (even if most of it is built from source).

Anyway, I don't want to bikeshed, only offer some suggestions before this gets more adoption.

[ViktorHofer]

I assume the former is going to stay on the repo build scripts?

Actually, the plan is to update all existing properties in the repositories that are part of the source-build graph to the new documented control set.

Thanks for the suggestions. We will talk about this in our next sync and consider your refinements 👍

[tmds]

Thanks.

Definitely on the top-level vmr build script, the flag is meant to convey build configuration for distro maintainers.

Building everything from source is an important trait of that build configuration, but we may want a name that conveys the use rather than the implementation.

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[MichaelSimons]

[Triage] This was resolved in dotnet/installer#18492.