How can I make msbuild understand that a .csproj file depends on the availability of an exe built by another .csproj - visual-studio

Question

I have a large VStudio solution whose .csproj files I'm porting over to the new .NET SDK format. I have integrated the github project with AppVeyor. When I work on the solution, my project is built by VStudio; AppVeyor uses msbuild to build my project.
All of the class library project files in the solution have been modified so that they specify <TargetFrameworks>netStandard2.0</TargetFrameworks>. For simplicity, let's represent the class library project files with classlib.csproj.
The solution also contains a few command-line tools, which need to be built in advance of some of the other projects, because those later projects need to run the command-line tools as a preprocessor before building themselves. These command-line projects are all specifying <TargetFrameworks>net472;netcoreapp2.0</TargetFrameworks>. Let's represent the tool project files with tool.csproj.
In order to build correctly, tool.csproj needs to be built before classlib.csproj. In the solution I've used the Build dependencies > Project dependencies command in the VStudio solution explorer to indicate this. This works fine when I'm working inside of VStudio.
However, when I push my changes to github, AppVeyor kicks off an msbuild process to build the projects. From the error spew, it's clear that the tool.csproj didn't get built in time. It seems msbuild doesn't understand the project dependency information in the .sln file.
Reading what's posted on the intertubes (e.g. https://devblogs.microsoft.com/visualstudio/incorrect-solution-build-ordering-when-using-msbuild-exe/), I attempted to add the following to classlib.csproj:
<ProjectReference Include="..\tool\tool.csproj">
<ReferenceOutputAssembly>false</ReferenceOutputAssembly>
</ProjectReference>
But when I do this I get the error:
Project '..\tool\tool.csproj' targets 'net472;netcoreapp2.0'. It cannot be referenced by a project that targets '.NETStandard,Version=v2.0'
which clearly makes sense.
Some other solutions I've read suggest editing the .sln file so that tool.csproj gets built first, and hope that building will be completed before classlib.csproj starts building. However, this is a race condition since msbuild is not aware of the dependency.
How, then, do I express that classlib.csproj depends on tool.csproj so that msbuild understands it?
EDIT
It turns out the issue was caused by an interaction between the target I'd written to start my tool and the globbing operation MSBuild does to resolve the <Compile> item collection using a pattern similar to **\*.cs. The tool generated the file after the globbing operation. Since the generated file isn't present when the globbing happens, it is missing from the <Compile> item collection, and the build failed. I mistakenly interpreted the error "foo.cs not found" as a failure to execute the tool, when in fact, it's a timing issue.

Answer 1

To make the build order works outside VS IDE, we need to use add reference
instead of BuildDependencies=>ProjectDependencies.
Right-click classlib project and choose add=>reference, in Project node choose the Tool Project you want like this:
Click ok to add it and save changes. After that, open the classlib.csproj you can find sentence like:
<ItemGroup>
<ProjectReference Include="..\xxx\Tools.csproj">
<Project>{6eaa430f-9793-4639-a84b-6ab767d57147}</Project>
<Name>Tools.csproj</Name>
</ProjectReference>
</ItemGroup>
This what the msbuild can understand. And I think that's what you want.
After that,you can use a single msbuild tool or Appveyor to check the
build order.
And in Appveyor, we can also disable the paralell builds(settings=>build=>msbuild options) to make sure it won't build classlib.csproj until the tools.csproj build ends.
The final build order in Appveyor will be what we defined in VS. Hope it helps.