https://github.com/mchehab/zbar/pull/115
--- a/zbarcam/zbarcam.c
+++ b/zbarcam/zbarcam.c
@@ -37,6 +37,7 @@
 #ifdef ENABLE_NLS
 #include "../zbar/gettext.h"
 # include <libintl.h>
+# include <locale.h>
 # define _(string) gettext(string)
 #else
 # define _(string) string
--- a/zbarimg/zbarimg.c
+++ b/zbarimg/zbarimg.c
@@ -42,6 +42,7 @@
 #ifdef ENABLE_NLS
 #include "../zbar/gettext.h"
 # include <libintl.h>
+# include <locale.h>
 # define _(string) gettext(string)
 #else
 # define _(string) string
-- 
2.26.2