Index: src/libexec/tradcpp/tradcpp.1
diff -u src/libexec/tradcpp/tradcpp.1:1.4 src/libexec/tradcpp/tradcpp.1:1.5
--- src/libexec/tradcpp/tradcpp.1:1.4	Wed Dec 28 17:47:11 2016
+++ src/libexec/tradcpp/tradcpp.1	Sun Sep  2 04:28:05 2018
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: tradcpp.1,v 1.4 2016/12/28 22:47:11 schwarze Exp $
+.\"	$OpenBSD: tradcpp.1,v 1.5 2018/09/02 08:28:05 jsg Exp $
 .\"
 .\" Copyright (c) 2013 The NetBSD Foundation, Inc.
 .\" All rights reserved.
@@ -27,7 +27,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 .\" POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: December 28 2016 $
+.Dd $Mdocdate: September 2 2018 $
 .Dt TRADCPP 1
 .Os
 .Sh NAME
@@ -261,6 +261,14 @@
 .El
 .Ss Diagnostic Options
 .Bl -tag -width bubblebabble
+.It Fl debuglog Ar file
+Write a trace of actions and operations to
+.Ar file
+as the input is processed.
+Meant for debugging problems in complex substitution schemes fed to
+.Nm ,
+such as those used by
+.Sy imake .
 .It Fl dD
 Dump all macro definitions, except for the predefined macros, after
 the normal preprocessing output.