thread(2): fix description of when/why procexec(l) functions return

diff --git a/sys/man/2/thread b/sys/man/2/thread
index e52289fc68b24ee8b01873b9a7f5ed18363913c7..510e0bfa838905885c003d28e1d55fdd4edaf699 100644 (file)
--- a/sys/man/2/thread
+++ b/sys/man/2/thread
@@ -332,7 +332,8 @@ and
 on success,
 they replace the calling thread (which must be the only thread in its proc)
 and invoke the external program, never returning.
-On error, they return \-1.
+On error, they return and set
+.IR errstr .
 If
 .I cpid
 is not null, the pid of the invoked program