diff --git a/tools/build/cross-build/include/common/exterr.h b/tools/build/cross-build/include/common/exterr.h
new file mode 100644
--- /dev/null
+++ b/tools/build/cross-build/include/common/exterr.h
@@ -0,0 +1,14 @@
+#ifndef _EXTERR_H_
+#define _EXTERR_H_
+
+#include <sys/types.h>
+
+static inline int
+uexterr_gettext(char *buf, size_t bufsz)
+{
+	if (bufsz > 0)
+		buf[0] = '\0';
+	return (0);
+}
+
+#endif
diff --git a/tools/build/cross-build/include/common/sys/exterrvar.h b/tools/build/cross-build/include/common/sys/exterrvar.h
new file mode 100644
--- /dev/null
+++ b/tools/build/cross-build/include/common/sys/exterrvar.h
@@ -0,0 +1,6 @@
+#ifndef _SYS_EXTERRVAR_H_
+#define _SYS_EXTERRVAR_H_
+
+#define	UEXTERROR_MAXLEN	256
+
+#endif