VMR source build targeting windows

[laifharwood]

From what I understand it isn't possible to do a VMR source build on a windows machine. Is it possible to do a source build on linux that targets windows?

[mthalman]

No, the source build infrastructure only outputs Linux binaries. While you can't directly run source build on a Windows machine, you can indirectly do it with WSL or Linux containers.

Related to #2910

[mmitche]

Adding some color to @mthalman's response:

There are two distinct concepts here that are closely related. First is source-build, which is when we can do a build of a single repo and produce a shipping product without 'prebuilts'; binaries that come in from the outside. Everything is produced from that single build. Today, this is only possible on Linux.

Whole product builds via the VMR. This is what we're developing over at https://github.com/dotnet/dotnet for .NET 10 and is closely related to source-build in its methodology, where we build the entire product from a single repo. This is/will be possible on Windows, Linux and Mac. However, this method of building does allow pre-builts. Prebuilt binaries do come in from the outside (e.g. we might restore a package that contains LLVM binaries or an Azure library).