Run Fake in the cibuild.ps1 file.

Octokit.sln

@@ -11,6 +11,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Build", "Build", "{CEC9D451
 	ProjectSection(SolutionItems) = preProject
 		build.cmd = build.cmd
 		build.fsx = build.fsx
+		script\cibuild.ps1 = script\cibuild.ps1
 		CustomDictionary.xml = CustomDictionary.xml
 		octokit.nuspec = octokit.nuspec
 		Octokit.Reactive.nuspec = Octokit.Reactive.nuspec

script/cibuild.ps1

@@ -72,7 +72,7 @@ if ($Clean) {
 
 Write-Output "Building Octokit..."
 Write-Output ""
-$output = .\Build-Solution.ps1 FullBuild Release -MSBuildVerbosity quiet 2>&1
+$output = .\"tools\FAKE.Core\tools\Fake.exe" "build.fsx"
 if ($LastExitCode -ne 0) {
     $exitCode = $LastExitCode