.net run elevated capturing output (F# FAKE build script)

build.fsx

#r @"packages/FAKE/tools/FakeLib.dll"
open Fake
let lprunPath = @"C:\ProgramData\LINQPad\Updates50\510\lprun.exe"

type System.String with
    static member Delimit delimiter (items:string seq) =
        String.Join(delimiter,items |> Array.ofSeq)
        
module Proc =
    // ExecProcess is a thin wrapper around Process.Start
    // docs at
    //   https://github.com/fsharp/FAKE/blob/master/src/app/FakeLib/ProcessHelper.fs#L184-L185
    //   https://github.com/fsharp/FAKE/blob/master/src/app/FakeLib/ProcessHelper.fs#L68-L107
    let ExecProcessElevated cmd args timeOut = 
        ExecProcess (fun si -> 
            si.Verb <- "runas"
            si.Arguments <- args
            si.FileName <- cmd
            si.UseShellExecute <- true) timeOut
  // wrapper for fake built-in in case we want the entire process results, not just the exitcode
  let runElevated cmd args timeOut =
      let tempFilePath = System.IO.Path.GetTempFileName()
      // hacky work around for not being able to capture output of an elevated process
      let resultCode = ExecProcessElevated "cmd" (sprintf "/c %s %s > %s" cmd args tempFilePath) timeOut
      trace "reading output results of runElevated"
      let outputResults = File.ReadAllLines tempFilePath
      File.Delete tempFilePath
      // idiomaticisizing the result, not needed, especially for uses outside of FAKE
      let processResult = ProcessResult.New resultCode (ResizeArray<_> outputResults) (ResizeArray<_>())
      (String.Delimit "\r\n" outputResults)
      |> trace
      processResult
      
(* more context of me calling it, in case something special caused it to work that wasn't included above *)


Target "SetupNode" (fun _ ->
    // install Choco
    // fake has a run elevated, let's see if that works
    //Sec.requireAdmin()
    let chocoPath =
        match Proc.findCmd "choco" with
        | Some x -> x
        | None ->
            let resultCode =
                ExecProcessElevated
                    "@powershell"
                    """-NoProfile -ExecutionPolicy Bypass -Command "iex ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'))" && SET "PATH=%PATH%;%ALLUSERSPROFILE%\chocolatey\bin" """
                    (TimeSpan.FromMinutes 3.)
            resultCode
            |> sprintf "choco install script returned %i"
            |> trace
            if resultCode <> 0 then
                failwithf "Task failed"
            // choco is installled, we think
            // probably won't work if it was just installed, the %path% variable given to/used by a process is immutable
            else
                // we could be wrong, check again
                match Proc.findCmd "choco" with
                | Some x -> x
                | None -> failwithf "choco was installed, in order for choco to be found or used, this has process has to be restarted"
    // check if our hack runElevated is actually elevated, test can provide rejection or support, not proof
    let hackResult = Proc.runElevated lprunPath @" ""C:\projects\LinqPad\LinqPad\LINQPad Queries\LpRun\requireAdmin.linq"" " (TimeSpan.FromSeconds 3.)
    trace (sprintf "hackResult: %A" hackResult)
    // choco install nodeJs
    let nodePath =
        let results = Proc.runElevated "echo" "hello admin" (TimeSpan.FromSeconds 3.)
        trace (sprintf "%A" results)
    ()


)

requireAdmin.fsx

// duplicate of the .linq file, but with syntax highlighting that github won't do in that file

module Sec = 
        open System.Security.Principal
        let getIsAdmin() =
            WindowsIdentity.GetCurrent()
            |> WindowsPrincipal
            |> fun wp -> wp.IsInRole(WindowsBuiltInRole.Administrator)
        let requireAdmin () = 
            let runningAsAdmin = getIsAdmin()
            if not runningAsAdmin then
                failwithf "Can't alter hosts file without admin permissions"
                
Sec.requireAdmin()
printfn "success!"
Console.WriteLine("success! admin did not throw")

requireAdmin.linq

<Query Kind="FSharpProgram" />

module Sec = 
        open System.Security.Principal
        let getIsAdmin() =
            WindowsIdentity.GetCurrent()
            |> WindowsPrincipal
            |> fun wp -> wp.IsInRole(WindowsBuiltInRole.Administrator)
        let requireAdmin () = 
            let runningAsAdmin = getIsAdmin()
            if not runningAsAdmin then
                failwithf "Can't alter hosts file without admin permissions"
                
Sec.requireAdmin()
printfn "success!"
Console.WriteLine("success! admin did not throw")