diff --git a/src/fsh.nim b/src/fsh.nim
index 7d9cbbd..cf3297c 100644
--- a/src/fsh.nim
+++ b/src/fsh.nim
@@ -164,7 +164,6 @@ proc evalVariable(vari: string): string =
   else:
     var e = newException(ShellVariableError, "No such variable: " & vari)
     e.variable = vari
-    e.msg = "No such variable: " & e.variable
     raise e
 
 # substitute does a substitution on the stream passed in
@@ -220,7 +219,9 @@ proc runBuiltin(builtin: string, args: openArray[string]): string =
   case builtin:
     of "set":
       if args.len < 2:
-        raise newException(Exception, "Set: not enough arguments provided")
+        var e = newException(ShellCommandError, "Set: not enough arguments provided")
+        e.command="set"
+        raise e
       shellVariables[args[0]] = args[1..^1].join(" ")
       return ""
     of "setenv":