FVWM: fvwm3 build error

Hi folks,

Trying to build fvwm3 on Debian I stumbled over this:

:
:
Making all in FvwmBacker
make[4]: Entering directory '/local/home/harri/debian/fvwm3/fvwm3-1.0.0/modules/FvwmBacker'
gcc -DHAVE_CONFIG_H -I. -I../..  -I../..   -Wdate-time -D_FORTIFY_SOURCE=2  -Wall -Wno-implicit-int -fno-common -g -O2 -fdebug-prefix-map=/local/home/harri/debian/fvwm3/fvwm3-1.0.0=. -fstack-protector-strong -Wformat -Werror=format-security -c -o FvwmBacker.o FvwmBacker.c
gcc -DHAVE_CONFIG_H -I. -I../..  -I../..   -Wdate-time -D_FORTIFY_SOURCE=2  -Wall -Wno-implicit-int -fno-common -g -O2 -fdebug-prefix-map=/local/home/harri/debian/fvwm3/fvwm3-1.0.0=. -fstack-protector-strong -Wformat -Werror=format-security -c -o root_bits.o root_bits.c
FvwmBacker.c: In function 'AddCommand':
FvwmBacker.c:703:7: error: format not a string literal and no format arguments [-Werror=format-security]
   703 |       CatString2("Unknown directive: ", line));
       |       ^~~~~~~~~~
cc1: some warnings being treated as errors
make[4]: *** [Makefile:540: FvwmBacker.o] Error 1
make[4]: Leaving directory '/local/home/harri/debian/fvwm3/fvwm3-1.0.0/modules/FvwmBacker'
make[3]: *** [Makefile:450: all-recursive] Error 1
make[3]: Leaving directory '/local/home/harri/debian/fvwm3/fvwm3-1.0.0/modules'
make[2]: *** [Makefile:510: all-recursive] Error 1
make[2]: Leaving directory '/local/home/harri/debian/fvwm3/fvwm3-1.0.0'
make[1]: *** [Makefile:451: all] Error 2
make[1]: Leaving directory '/local/home/harri/debian/fvwm3/fvwm3-1.0.0'


I had to set -Wno-error=format-security to make.

Patch is attached.


Regards
Harri

--- modules/FvwmBacker/FvwmBacker.c.orig	2020-08-17 00:59:05.000000000 +0200
+++ modules/FvwmBacker/FvwmBacker.c	2020-09-06 20:24:09.046545910 +0200
@@ -699,8 +699,7 @@
 	}
 	else
 	{
-		fvwm_debug(__func__,
-			   CatString2("Unknown directive: ", line));
+		fvwm_debug(__func__, "Unknown directive: %s", line);
 		return;
 	}
 	this->flags.do_ignore_desk = do_ignore_desk;