File gcc9-printf-s-null-argument.patch of Package ltrace

--- output.c	2014-09-02 13:39:08.000000000 +0200
+++ ./output.c.new	2019-01-04 15:22:52.118045911 +0100
@@ -658,7 +658,7 @@
 
 	/* This mimics the output produced by libunwind below.  */
 	fprintf(options.output, " > %s(%s+0x%" PRIx64 ") [%" PRIx64 "]\n",
-		modname, symname, off, pc);
+		modname ?: "(null)", symname ?: "(null)", off, pc);
 
 	/* See if we can extract the source line too and print it on
 	   the next line if we can find it.  */