diff --git a/src/Grains.fs b/src/Grains.fs
index 54c1447..9d07e7b 100644
--- a/src/Grains.fs
+++ b/src/Grains.fs
@@ -6,6 +6,7 @@ open System.Threading
 open System.Threading.Tasks
 
 open Bidello.Datatypes
+open Bidello.Shell
 
 
 type IShellGrain = 
@@ -18,14 +19,26 @@ type ShellGrain() =
 
     interface IShellGrain with
         member _.schedule (ct) (jobs: ChainOfJobs) = task {
-             // printfn "Grain view: --------"
-             // printfn "HEAD= %A" jobs.head
-             // jobs.rest |> List.iter (printfn "%A")
-             // printfn "--------"
             let! rc = 
                 jobs.head
-                |> Shell.run_job
-            match rc with
-            | Ok rc -> printfn "rc = OK %A" rc
-            | Error rc -> printfn "rc = Error %A" rc
-        }
+                |> run_job
+(*
+            let rec run = function
+            | [] -> ()
+            | x::xs ->
+                let! rc = run_job x
+            
+                match rc with
+                | NoShell reason | Unknown reason  ->
+                    printfn "Greve: %A" reason
+                | Success stdout -> printfn "rc = Ok %A" stdout
+                | NoPermissionOnFolder -> printfn "NO perms on folder"
+                | NoPrivilegeToUser -> printfn "NO privilege to user"
+                | Failure (_rc, stderr) -> printfn "rc ERror = = stderr %A" stderr
+
+                run xs
+
+            run (jobs.head::jobs.rest)
+            *)
+            failwith "todoo"
+}
diff --git a/src/Shell.fs b/src/Shell.fs
index bbec54f..67b99b8 100644
--- a/src/Shell.fs
+++ b/src/Shell.fs
@@ -29,6 +29,33 @@ let private shell_ () =
 
 let shell = Lazy.Create shell_
 
+let private has_permission_on_folder (shell: string) (folder: string) (user: string) = task {
+    try
+        let! rc = 
+            Builder
+                .UseShell(shell)
+                .UseExecutable("true")
+                .UseStartInfoTransform(fun si ->
+                                        si.WorkingDirectory <- folder
+                                        si.UserName <- user)
+                .ExecuteAsync ()
+        return true
+    with _ -> return false
+}
+
+let private can_switch_to_user (shell: string) (user: string) = task {
+    try
+        let! rc = 
+            Builder
+                .UseShell(shell)
+                .UseExecutable("true")
+                .UseStartInfoTransform(fun si -> si.UserName <- user)
+                .ExecuteAsync ()
+        return true
+    with _ -> return false
+}
+    
+
 let which (executable: string) =
     let run (shell: string) =
         let rc = 
@@ -56,6 +83,7 @@ let which (executable: string) =
 type RunResult =
     | Success of string | Failure of (int * string)
     | Unknown of string | NoShell of string
+    | NoPermissionOnFolder | NoPrivilegeToUser
 
 let run_job (cj: CronJob) = task {
 
@@ -92,6 +120,18 @@ let run_job (cj: CronJob) = task {
     match shell.Value with
     | Error e -> return NoShell e
     | Ok shell ->
-        printfn $"Running: {executable}|{shell}|{workdir}|{user}"
-        return! run shell
+        let! rc = run shell
+
+        match rc with
+        | Unknown u ->
+            let! can_switch = can_switch_to_user shell user
+            if not can_switch then
+                return NoPrivilegeToUser
+            else
+                let! can_cwd = has_permission_on_folder shell workdir user
+                if not can_cwd then 
+                    return NoPermissionOnFolder
+                else
+                    return Unknown u
+         | rc -> return rc 
 }
diff --git a/tests/UnitTest1.fs b/tests/UnitTest1.fs
index 4aef5f1..8b7ab5b 100644
--- a/tests/UnitTest1.fs
+++ b/tests/UnitTest1.fs
@@ -98,3 +98,19 @@ let should_fail_no_host () =
     Cron.sort_jobs now requirements
     |> Result.isError
     |> Assert.is_true
+
+[<Test>]
+let job_deps_chain () =
+    
+    let requirements = [
+        {bj with job_name = "j1"}
+        {bj with job_name = "j2_after_j1"; ``when``="@after j2"}
+        {bj with job_name = "j3_after_j2"; ``when``="@after j2_after_j1"}
+    ]
+
+    let cjs = run_function requirements
+
+    let expected = [[("h1", "j1"); ("h1", "j1_after")];
+                    [("h1", "j2"); ("h1", "j2_after")];
+                    [("h2", "j1")]]
+    Assert.are_seq_equal expected cjs