OpenBSD has ncurses in base.

Index: Makefile
--- Makefile.orig
+++ Makefile
@@ -4,8 +4,7 @@ PREFIX    ?= /usr/local
 MANPREFIX ?= $(PREFIX)/man
 CPPFLAGS += -DVERSION_STR='"$(VERSION)"'
 CFLAGS += -Wall -Wextra
-CFLAGS += `pkg-config --cflags ncursesw`
-LDLIBS += `pkg-config --libs ncursesw` -lm
+LDLIBS += -lcurses -lm
 
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