This assumes root privilege...

--- util-hurd-0.0.20130212.orig/nsmux/Makefile.am
+++ util-hurd-0.0.20130212/nsmux/Makefile.am
@@ -45,7 +45,6 @@ nsmux_SOURCES = \
   trans.c
 
 nsmux_CPPFLAGS = \
-  -DDEBUG \
   $(AM_CPPFLAGS)
 
 nsmux_LDADD = \
