Attempt all publishing tasks, and fail build if one of them fails

build.cake

//////////////////////////////////////////////////////////////////////
// PARAMETERS
//////////////////////////////////////////////////////////////////////

bool publishingError = false;

///////////////////////////////////////////////////////////////////////////////
// SETUP / TEARDOWN
///////////////////////////////////////////////////////////////////////////////

//////////////////////////////////////////////////////////////////////
// TASKS
//////////////////////////////////////////////////////////////////////

Task("Upload-AppVeyor-Artifacts")
    .Does(() =>
{
    Information("Upload-AppVeyor-Artifacts");
});

Task("Publish-MyGet")
    .ContinueOnError()
    .Does(() =>
{
    Information("Publish-MyGet");
})
.ReportError(exception =>
{
    Information("Failed Publish-MyGet");
    publishingError = true;
});

Task("Publish-NuGet")
    .ContinueOnError()
    .Does(() =>
{
    Information("Publish-NuGet");
})
.ReportError(exception =>
{
    Information("Failed Publish-NuGet");
    publishingError = true;
});

Task("Publish-Chocolatey")
    .ContinueOnError()
    .Does(() =>
{
    Information("Publish-Chocolatey");
    throw new Exception("Deliberately failing choco task...");
})
.ReportError(exception =>
{
    Information("Failed Publish-Chocolatey");
    publishingError = true;
});

Task("Publish-HomeBrew")
    .ContinueOnError()
	.Does(() =>
{
    Information("Publish-Homebrew");
})
.ReportError(exception =>
{
    Information("Failed Publish-HomeBrew");
    publishingError = true;
});

Task("Publish-GitHub-Release")
    .ContinueOnError()
    .Does(() =>
{
    Information("Publish-GitHub-Release");
})
.ReportError(exception =>
{
    Information("Failed Publish-GitHub-Release");
    publishingError = true;
});

//////////////////////////////////////////////////////////////////////
// TASK TARGETS
//////////////////////////////////////////////////////////////////////

Task("AppVeyor")
  .IsDependentOn("Upload-AppVeyor-Artifacts")
  .IsDependentOn("Publish-MyGet")
  .IsDependentOn("Publish-NuGet")
  .IsDependentOn("Publish-Chocolatey")
  .IsDependentOn("Publish-HomeBrew")
  .IsDependentOn("Publish-GitHub-Release")
  .Finally(() =>
{
    if(publishingError)
    {
        throw new Exception("An error occurred during the publishing of Cake.  All publishing tasks have been attempted.");
    }
});

//////////////////////////////////////////////////////////////////////
// EXECUTION
//////////////////////////////////////////////////////////////////////

RunTarget("AppVeyor");

cake.log

========================================
Upload-AppVeyor-Artifacts
========================================
Upload-AppVeyor-Artifacts

========================================
Publish-MyGet
========================================
Publish-MyGet

========================================
Publish-NuGet
========================================
Publish-NuGet

========================================
Publish-Chocolatey
========================================
Publish-Chocolatey
An error occured when executing task 'Publish-Chocolatey'.
Failed Publish-Chocolatey

========================================
Publish-HomeBrew
========================================
Publish-Homebrew

========================================
Publish-GitHub-Release
========================================
Publish-GitHub-Release

========================================
AppVeyor
========================================
Error: An error occurred during the publishing of Cake.  All publishing tasks have been attempted.