Avoid node reuse during desktop-hosted builds

[rainersigwald]

If msbuild is invoked with the (default) /nodeReuse:true argument,
worker nodes hang around for a period of time after the build is complete
to see if more work will be incoming. This is normally a nice
startup-time-reducing perf optimization. But in our own build, it means
that many newly-created MSBuild assemblies are opened and uneditable,
failing builds and causing cleans to fail.

Changing the Windows build script to just always pass /nodeReuse:false.

[jeffkl]

LGTM

[rainersigwald]

D'oh, forgot that we dropped that switch entirely on core, not just made it a no-op.

[jeffkl]

Is this because there is no node reuse on core? Or you can't turn it off on core?

[rainersigwald]

@jeffkl You can't turn it on. The way it's implemented on Windows uses a named pipe named after the PID, so you can enumerate all MSBuild processes and ask if they're available for your use. But that's a potential elevation-of-privilege attack if you can talk to an elevated process (or another user) while yourself running in low-priv mode. Windows provides APIs to check that both sides of the pipe are the same user + elevation level, but other OSes don't, so we just cut the feature for Core. See 86f213b and #506.

[jeffkl]

Interesting, well then I'm sure you know what to do, conditionally add the argument...

[cdmihai]

Can you branch whether to use the switch or not in the caller of build.cmd? I think that one knows what the targeting configuration is.

[rainersigwald]

Yeah, I'll do that in the next iteration, as soon as I get a free minute.

[rainersigwald]

Turned out to be easier to branch inside build.cmd but after checking for a host.

[AndyGerlicher]