$OpenBSD: patch-config_mk,v 1.1.1.1 2017/10/23 21:39:20 bcallah Exp $

Index: config.mk
--- config.mk.orig
+++ config.mk
@@ -4,15 +4,15 @@ VERSION = 3
 # Customize below to fit your system
 
 # paths
-PREFIX = /usr/local
+PREFIX ?= /usr/local
 MANPREFIX = ${PREFIX}/man
 
 # flags
 CPPFLAGS = -D_DEFAULT_SOURCE
-CFLAGS   = -std=c99 -pedantic -Wall -Wextra -Os
-LDFLAGS  = -s
+CFLAGS   += -std=c99 -pedantic -Wall -Wextra -I${LOCALBASE}/include
+LDFLAGS  += -s -L${LOCALBASE}/lib
 PNG-LDFLAGS = -lpng
 JPG-LDFLAGS = -ljpeg
 
 # compiler and linker
-CC = cc
+CC ?= cc
