Try C.UTF-8 which is also a commonly useful locale on some platforms,

from Romain Francoise.

diff --git a/usr.bin/tmux/tmux.c b/usr.bin/tmux/tmux.c
index 09a649c..8c68c31 100644 (file)
--- a/usr.bin/tmux/tmux.c
+++ b/usr.bin/tmux/tmux.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tmux.c,v 1.182 2017/04/22 12:08:41 nicm Exp $ */
+/* $OpenBSD: tmux.c,v 1.183 2017/07/03 08:08:30 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -196,7 +196,8 @@ main(int argc, char **argv)
        int                                      opt, flags, keys;
        const struct options_table_entry        *oe;
 
-       if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL) {
+       if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL &&
+           setlocale(LC_CTYPE, "C.UTF-8") == NULL) {
                if (setlocale(LC_CTYPE, "") == NULL)
                        errx(1, "invalid LC_ALL, LC_CTYPE or LANG");
                s = nl_langinfo(CODESET);