PMC Tools: Build only the active project, not the whole solution

[ajcvickers]

We tried to do this before, but ran into issues. Hopefully the project system has matured such that it is now possible. See #9515 for more discussion.

[bricelam]

Note, this only applies to the PMC Tools. The CLI tools already only build the startup project.

[syndicatedshannon]

Thank you @bricelam . That wasn't made clear or I missed it on other threads. Knowing that, I can probably build a tooling workaround, except for the fact that I have other issues getting CLI working for EF Core 2.0 :( . I'll switch my focus to fixing those.

[Mike-E-angelo]

It would be neat to have this, as this is the only reason I typically use PMC. 😁

[Mike-E-angelo]

Unfortunately using the dotnet ef equivalent seems to invalidate all projects in my solution, seemingly replacing one problem with another.

First, I run dotnet clean and SHIFT-CTRL-B on my SLN:

========== Build: 130 succeeded, 0 failed, 0 up-to-date, 0 skipped ==========

SHIFT-CTRL-B again to be sure:

========== Build: 0 succeeded, 0 failed, 130 up-to-date, 0 skipped ==========

I then run the following commands:

dotnet ef database drop -f -v --project Starbeam.Model.Schema --startup-project Starbeam.Model.Schema
dotnet ef migrations remove -v --project Starbeam.Model.Schema --startup-project Starbeam.Model.Schema
dotnet ef migrations add Initial -v --project Starbeam.Model.Schema --startup-project Starbeam.Model.Schema

Finally, after that is complete, I run SHIFT-CTRL-B once more:

========== Build: 129 succeeded, 0 failed, 1 up-to-date, 0 skipped ==========

FWIW this is with 6.0.0-rc.2.21452.6 tools.