[Built-in analyzer] Flag shared evaluations between restore and build targets

[ViktorHofer]

See https://github.com/dotnet/runtime/blob/6d0a902c9585d98bfa44f514bac21a47eabe02fa/eng/testing/workloads-testing.targets#L195-L200 as an example.

Because the Restore and Pack target pass the same set of properties in, the underlying project evaluation evaluation is shared. This resulted in msbuild files restored via a PackageReference not being imported during the build.

I have been fixing so many of these code pieces in my career at Microsoft and it would really be helpful if msbuild could somehow indicate that a shared evaluation between Restore and Build or Pack is most certainly wrong. Sure, there are cases where a shared evaluation might be intentional, but that should < 1%.

Related: #2811

cc @akoeplinger @ericstj

[rainersigwald]

The error should be clear that just having different evaluations is not enough, they have to be in separate executions.

[lambdageek]

different evaluations is not enough, they have to be in separate executions.

@rainersigwald I'm a bit unclear on what that means. Does that mean that this is not a valid workaround?

<Target Name="RestoreBuildAndPublishSubproject">
        <MSBuild Projects="SomeSubproject.csproj"
                 Properties="Configuration=$(NativeLibsPublishConfiguration);RuntimeIdentifier=$(OutputRID);NativeLib=$(NativeLibKind);_RandomPropertyToPleaseMSBuild=Restoring"
                 Targets="Restore" />

        <MSBuild Projects="SomeSubproject.csproj"
                 Properties="Configuration=$(NativeLibsPublishConfiguration);RuntimeIdentifier=$(OutputRID);NativeLib=$(NativeLibKind);_RandomOtherPropertyToPleaseMSBuild=BuildingAndPublishing"
                 Targets="Build;Publish" />
</Target>

[rainersigwald]

@lambdageek correct. The failure mode is:

1. The project has references that include MSBuild logic (build/PackageName.props).
2. Restore.
3. Change something such that the packages that include the MSBuild logic are changed (bump the patch version of a reference, say).
4. Execute the Restore;Build or something like the workaround you posted.

Inside 4, the timeline goes like

1. Evaluate projects, including the .nuget.g.props file that was created in 3.
2. Do restore stuff, download the packages, whatever.
3. As part of that restore, update .nuget.g.props on disk to point to the new package version.
4. Enter the Build part.
   a. If it was via Restore;Build this reuses the evaluation from 1, so still uses the old package version.
   b. If there's a new global property, the MSBuild engine reevaluates the project, but because it's part of the same build session it has an internal cache of the XML of all imports, when it reprocesses .nuget.g.props it's still the old version.

We considered allowing invalidating the XML cache in that scenario but it turns out to be load-bearing for some cases including Live Unit Testing and some builds that try to bump their own version mid-build.

Things work most of the time because it's not super common to bump the versions of packages that have build logic . . . but that's not 100%.