MKSH_NOPROSPECTOFWORK has no co-processes. at all.

check.t

@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.409 2011/02/18 22:26:06 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.410 2011/02/19 21:39:14 tg Exp $
 # $OpenBSD: bksl-nl.t,v 1.2 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: history.t,v 1.5 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: read.t,v 1.3 2003/03/10 03:48:16 david Exp $
@@ -4481,6 +4481,7 @@ stdin:
 name: regression-65
 description:
 	check for a regression with sleep builtin and signal mask
+category: !nojsig
 time-limit: 3
 stdin:
 	sleep 1