Example build.cake file for .NET Core 2.0

build.cake

```csharp

// https://github.com/Microsoft/msbuild/issues/2532
// env var "MSBuildSDKsPath" needs to be set to the correct "sdks" subfolder

// Other refs: https://cakebuild.net/api/ & https://cakebuild.net/docs/fundamentals/asynchronous-tasks

using System.Threading;
using Cake.Common.Tools.DotNetCore;
using Cake.Common;

var target = Argument ("target", "Default");

var programProjects = new [] {
    "./src/Exe1/Exe1.csproj",
    "./src/Exe2/Exe2.csproj",
};

// Its possible the Linux Subsystem on Windows may say Linux is present; not sure.
// In any case, make sure the .csproj files are also correct!
string runtimeString(){
    if (IsRunningOnWindows()) return "win-x64";
    return "linux-x64";
}

// First build a functions library, then build EXEs in parallel
Task ("Default")
    .IsDependentOn ("Build_Library")
    .Does (() => BuildInParallel (programProjects));

// Critical task: build a common functions library
Task ("Build_Library")
    .Does (() => DotNetCorePublish ("./src/Library/Library.csproj", new DotNetCorePublishSettings {
        Framework = "netstandard2.0",
        Configuration = "Release",
        OutputDirectory = "./bin/",
        Runtime = runtimeString()
    }));

// Parallel build task: build the EXEs
public void BuildInParallel (
    IEnumerable<string> filePaths,
    int maxDegreeOfParallelism = -1,
    CancellationToken cancellationToken = default (CancellationToken)) {

    // Create an array of actions, based on the number of given projects
    var actions = new List<Action> ();
    var settings = new DotNetCorePublishSettings {
        Framework = "netcoreapp2.0",
        Configuration = "Release",
        OutputDirectory = "./bin/",
        Runtime = runtimeString()
    };
    foreach (var filePath in filePaths) {
        actions.Add (() => DotNetCorePublish (filePath, settings));
    }

    // Fire off parallel jobs, based on array of actions
    Parallel.Invoke (new ParallelOptions {
        MaxDegreeOfParallelism = maxDegreeOfParallelism,
            CancellationToken = cancellationToken
    }, actions.ToArray ());
}

// Entry point
RunTarget (target);
```