anchor.diff:          member __.``1. Primitive: System.Guid`` () = Check.QuickThrowOnFail<Guid> testEquals
   
           [<Test; Category("Primitives")>]
  -        member __.``1. Primitive: bigint`` () = Check.QuickThrowOnFail<bigint> testEquals
  +        member __.``1. Primitive: bigint`` () = 
  +            if runsOnMono then
  +                // Mono bug: https://bugzilla.xamarin.com/show_bug.cgi?id=20456
  +                Check.QuickThrowOnFail<bigint> (fun i -> let j = testRoundtrip i in i.ToString() = j.ToString())
  +            else
  +                Check.QuickThrowOnFail<bigint> testEquals
   
           [<Test; Category("Bytes")>]
           member __.``1. Primitive: byte []`` () = testEquals (null : byte []) ; Check.QuickThrowOnFail<byte []> testEquals
  
positive.code:                 let t' = pickler.Deserialize<'T>(m)
                  ()
              with
              | :? InvalidPickleException -> ()
  
          [<Test; Category("Stress tests")>]
          member t.``8. Stress test: arbitrary data deserialization`` () =
  
negative.code:             Check.QuickThrowOnFail<Tuple<string>> testEquals
              Check.QuickThrowOnFail<string * byte> testEquals
              Check.QuickThrowOnFail<string * byte * DateTime> testEquals
              Check.QuickThrowOnFail<string * byte * DateTime * Guid> testEquals
              Check.QuickThrowOnFail<string * byte * DateTime * Guid * int> testEquals
              Check.QuickThrowOnFail<string * byte * DateTime * Guid * int * uint64> testEquals
              Check.QuickThrowOnFail<string * byte * DateTime * Guid * int * uint64 * decimal> testEquals
              Check.QuickThrowOnFail<string * byte * DateTime * Guid * int * uint64 * decimal * int> testEquals
              Check.QuickThrowOnFail<string * byte * DateTime * Guid * int * uint64 * decimal * int * int> testEquals
  
          [<Test; Category("Generic BCL Types")>]
          member __.``4. BCL: tuple nested`` () =
  