http://blog.ctaggart.com/2013/10/tfs-with-f-make.html

build.fsx

#r @"packages\FAKE.2.1.309-alpha\tools\FakeLib.dll"

#r @"C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE\ReferenceAssemblies\v2.0\Microsoft.TeamFoundation.Build.Client.dll"
#r @"C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE\ReferenceAssemblies\v2.0\Microsoft.TeamFoundation.Client.dll"

open Fake
open Microsoft.TeamFoundation.Client
open Microsoft.TeamFoundation.Build.Client
open System

let buildDir  = "bin"
let sln = !+ @"TFS.sln" |> Scan

Target "BuildNumber" (fun _ ->
    if hasBuildParam "tfsTeamProjectCollectionUri" && hasBuildParam "tfsBuildDetailUri" then
        let tfsTeamProjectCollectionUri = getBuildParam "tfsTeamProjectCollectionUri"
        let tfsBuildDetailUri = getBuildParam "tfsBuildDetailUri"
        sprintf "tfsTeamProjectCollectionUri: %s" tfsTeamProjectCollectionUri |> trace
        sprintf "tfsBuildDetailUri: %s" tfsBuildDetailUri |> trace

        use tfs = new TfsTeamProjectCollection(Uri tfsTeamProjectCollectionUri);
        let bs = tfs.GetService<IBuildServer>();
        let b = bs.GetBuild(Uri tfsBuildDetailUri)
        b.BuildNumber <- "FAKE " + b.BuildNumber
        b.Save()
)

Target "Clean" (fun _ -> 
    CleanDirs [buildDir]
)

Target "Build" (fun _ ->
    MSBuildRelease buildDir "rebuild" sln |> Log ""
)
 
"Build" <== ["Clean"; "BuildNumber"]

Run "Build"