Mine

Invalid argument
Invalid argument
    while executing
"hal net testbittwo <= m5i20.0.in-04"
    ("eval" body line 1)
    invoked from within
"eval hal $what"
    (procedure "showEx" line 3)
    invoked from within
"showEx $halcommand"
    invoked from within
".main.note.fps.b.execute invoke"
    ("uplevel" body line 1)
    invoked from within
"uplevel #0 [list $w invoke]"
    (procedure "tk::ButtonUp" line 22)
    invoked from within
"tk::ButtonUp .main.note.fps.b.execute"
    (command bound to event)