+--- src/bm_unix.c~ 2013-08-25 11:59:33.000000000 -0700
++++ src/bm_unix.c 2017-01-03 23:37:36.697875250 -0800
+@@ -260,7 +260,6 @@
+ vgetc()
+ {
+ char cha;
+- extern int errno;
+
+ errno = 0;
+ if (read(2, &cha, 1) <= 0) {
+--- src/bvi.c~ 2014-10-07 13:09:45.000000000 -0700
++++ src/bvi.c 2017-01-03 23:37:09.469794620 -0800
+@@ -729,7 +729,6 @@
+ char *arg;
+ {
+ off_t val;
+- extern int errno;
+ char *poi;
+
+ errno = 0;
+--- src/comm.c~ 2014-01-29 06:54:53.000000000 -0800
++++ src/comm.c 2017-01-03 23:37:18.305820838 -0800
+@@ -84,7 +84,6 @@
+ extern char *name; /* actual filename */
+ extern char **files; /* used for "next" and "rewind" */
+ extern int numfiles, curfile;
+-extern int errno;
+
+ static char oldbuf[CMDSZ]; /** for :!! command **/
+